Mei Xiang, the female giant panda that lost its baby last month, takes a nap after being fed a frozen fruit treat at the National Zoo. Chief veterinarian Suzan Murray said a necropsy showed the tiny cub’s lungs were not fully formed. That impeded the flow of oxygen, leading to liver necrosis, or the death of liver cells. 
 
 Oct. 11, 2012 Mei Xiang, the female giant panda that lost its baby last month, takes a nap after being fed a frozen fruit treat at the National Zoo. Chief veterinarian Suzan Murray said a necropsy showed the tiny cub’s lungs were not fully formed. That impeded the flow of oxygen, leading to liver necrosis, or the death of liver cells. Astrid Riecken/For The Washington Post 
 
 Liver failure caused by an insufficient supply of oxygen caused the death of the giant panda cub last month at the National Zoo. 
 
 The giant panda cub born a week ago at the National Zoo in Washington has died; the cause was not immediately known, zoo officials said Sunday. 
 
 The giant panda cub born a week ago at the National Zoo in Washington has died; the cause was not immediately known, zoo officials said Sunday. 
 
 The body of the stricken panda cub rested on a blue blanket in a keepers’ room at the National Zoo. The veterinarian had been trying in vain to revive the animal. But nothing was working. Should she keep going? 
 
 The room, filled with stunned keepers and curators, was still. It had been over an hour since the cub was spotted lifeless in the den. Chief giant panda curator Brandie Smith didn’t want the effort to stop, but she knew it was futile. 
 
 Should the resuscitation continue? 
 
 “No,” Smith said. 
 
 People hugged and wept. And for a few moments Sunday morning in the quiet of the panda house, the animal’s body, outwardly perfect, was left on the blanket so the staff could grieve. 
 
 Smith and other zoo officials, who recounted the scene, said Monday that a necropsy performed on the cub’s body showed unusual fluid in its abdomen and irregularities in its liver. But it was not clear if that played a role in the animal’s demise. 
 
 The zoo’s chief veterinarian, Suzan Murray, said at a news conference that results of lab tests on tissue samples, expected within the next week or so, could help identify the cause of death. 
 
 The cub, born Sept. 16, had heart and lungs that appeared normal, suggesting that suffocation was not a factor, Murray said. There was milk in the cub’s digestive tract, a sign that it had been nursing successfully. 
 
 Murray said that the cub appears to have been female, although it was so small that lab tests will be needed to confirm that finding. Even without a conclusive ruling, she said, zoo officials have decided to refer to the cub as a “she.” 
 
 The cub’s surprise birth came after five failed attempts to impregnate the zoo’s female adult giant panda, Mei Xiang, and experts thought the chance of her having another cub was less than 10 percent. 
 
 Zookeepers were overjoyed, and zoo director Dennis Kelly said last week it was a glorious event for the Washington area. 
 
 Monday, though, zoo officials were drawn and emotional in recounting details of the cub’s death. 
 
 “We were living the promise,” Smith, the panda curator, said at the zoo, her eyes filling with tears. “The promise of all these years to come, and how amazing it was going to be. 
 
 “Part of it is . . . the loss of this animal, but it’s also the loss of all that wonder that we were about to be a part of,” she said. “How much fun we were all going to have.” 
 
 Smith said the cub appeared to be doing fine early Sunday morning. 
 
 “We saw the cub . . . at 8:30,” she said. “It was squirming. It was moving.” She said Mei Xiang was holding the cub and both looked well. 
 
 Suddenly, about 45 minutes later, Mei Xiang got up and began honking in “distressed vocalization” for about 30 seconds, and keepers saw that the cub had stopped moving. 
 
 An emergency was declared. The cub was removed from the den and rushed to the keepers’ room in the panda house. There, zoo veterinarian Nancy Boedeker began heart massage while staff members, including director Kelly, looked on. 
 
 Tense minutes passed. 
 
 Smith remembered that the cub was a “beautiful little baby. Absolutely beautiful. Perfectly formed. . . . Black spots were just starting to come out on its eyes. Just a beautiful little baby panda.” 
 
 The atmosphere in the room was subdued. 
 
 “This has been a dream,” she said. “We’ve all been in this kind of state of suspended disbelief that something so magical [had] happened to us. Everyone just stopped and watched and waited. All feelings, all emotions were suspended for that moment in time. All we could do was hope that the cub would be fine.” 
 
 Finally, Boedeker said she believed resuscitation efforts were futile, although she would continue if the curators wanted. 
 
 “I said I wanted her to continue because that way we could put off the inevitable,” Smith said. “But at that point, I said ‘No.’ It’s like we were in a bubble. I didn’t want the bubble to pop.” 
 
 Once it did, Don Moore, the zoo’s associate director for animal-care sciences, said it was important to let the staff grieve. So the cub’s body was left on the table surrounded by those who were dedicated to taking care of it. 
 
 “It was like any death,” Smith said. “We grabbed each other. We hugged each other. We cried.” 
 
 Meanwhile, zoo officials said Monday that Mei Xiang appears to be coping well. She slept soundly in her den and has ventured out to eat and drink and interact with her keepers — behaviors she had eschewed at the end of her pregnancy and since the cub was born. 
 
 But she is still cradling a toy in her den, much as she cradled her cub during its brief life. Murray and Kelly said the cradling behavior is one sign that Mei Xiang has not transitioned away from the mothering role. 
 
 The cub’s sudden death seems to have upset, for the moment, all the plans for a new era of giant pandas at the National Zoo and in the Washington region. Kelly said Monday he had not had a chance to think much about the future. 
 
 Giant panda cubs, like many newborns at the zoo, are extremely fragile. A total of six giant panda cubs have died at the zoo, going back to the 1980s. A seventh cub was stillborn. The only cub to survive into maturity has been Tai Shan, who was born to Mei Xiang and Tian Tian in 2005 and was sent to China in 2010. ||||| The giant panda cub born a week ago at the National Zoo in Washington died Sunday morning, saddening zoo officials and visitors who had heralded its unexpected arrival. 
 
 FILE - In this Dec. 19, 2011 file photo shows Mei Xiang, the female giant panda at the Smithsonian's National Zoo in Washington. The panda cub born to Mei Xiang on Sept. 16, 2012, after five consecutive... (Associated Press) 
 
 The 4-ounce (113-gram) cub, about the size of a stick of butter, showed no obvious signs of distress and made its final recorded noise shortly before 9 a.m. Sunday, zoo officials said at a news conference. 
 
 The cub's mother, Mei Xiang, then made an unusual honking sound at 9:17 a.m. that her keepers interpreted as a distress call, and she moved away from where she had been nesting with the cub. About an hour later, one keeper distracted her with honey water while another used an instrument similar to a lacrosse stick to pick up the cub. 
 
 The cub, whose gender could not be determined externally, was not breathing and its heart had stopped. A veterinarian attempted CPR before it was pronounced dead at 10:28 a.m. 
 
 "This is devastating for all of us here," National Zoo director Dennis Kelly said at a news conference. "It's hard to describe how much passion and energy and thought and care has gone into this." 
 
 Four American zoos have pandas, but Washington's pandas are treated like royalty. The zoo was given its first set of pandas in 1972 as a gift from China to commemorate President Richard Nixon's historic visit to the country. 
 
 Mei Xiang's first cub, Tai Shan, born in 2005, enjoyed enormous popularity before he was returned to China in 2010. 
 
 The new cub, born Sept. 16, had been a surprise at the zoo. Fourteen-year-old Mei Xiang had five failed pregnancies before giving birth. 
 
 Panda cubs are especially delicate and vulnerable to infection and other illness. The first weeks of life are critical for the cubs as mothers have to make sure they stay warm and get enough to eat. 
 
 Panda mothers are about 1,000 times heavier than their cubs, and sometimes they accidentally crush them. On any given day in the first two weeks of life, cubs have a mortality rate of 17 to 18 percent, zoo officials said. 
 
 A necropsy was being conducted to determine the cause of death, and preliminary findings were expected Monday, said Suzan Murray, the zoo's chief veterinarian. The cub showed no external signs of trauma, Murray said. 
 
 "The cub was just beautiful. Beautiful little body, beautiful face, with markings just beginning to show around the eye," Murray said. 
 
 As they did after Tai Shan was born, keepers had been leaving Mei Xiang alone with her offspring, monitoring her on video feeds that were also streamed on the zoo's website. Mei Xiang was resting comfortably after the cub's death, officials said. 
 
 The zoo's first panda couple, Ling Ling and Hsing Hsing, had five cubs during the 1980s, but none lived more than a few days. One of the cubs was stillborn; two others died of pneumonia within a day; another died from lack of oxygen after birth; and the final cub died of an infection after four days. 
 
 Atlanta has had three cubs, and the San Diego zoo has had six, including a cub born this year. A panda couple in Memphis has yet to have a cub, despite several tries. 
 
 The cub had not yet been named in accordance with Chinese tradition _ it was to receive a name after 100 days on Dec. 24. Had the cub survived until then, it would have been roughly the size of a loaf of bread and weighed around 10 pounds (4.5 kilograms). It will not be named posthumously, Kelly said. 
 
 Kelly said it was too soon to know if the zoo would attempt to breed Mei Xiang again. She was artificially inseminated with sperm from the zoo's male panda, Tian Tian. 
 
 "These bears are so critically endangered that every panda cub is important," Kelly said. 
 
 The panda exhibit was closed indefinitely. Early Sunday afternoon, there was still a sign outside the panda house announcing the cub's birth, and many visitors were unaware of the death. 
 
 At the zoo's panda-themed gift shop, Diana Salguero, 24, of Manassas, Virginia, was trying on a headband with panda ears when she learned from a reporter about the cub's death. 
 
 "I want to cry right now," she said. "I'm heartbroken. I've been excited all week. That's why I came out today." 
 
 ___ 
 
 Follow Ben Nuckols on Twitter at http://twitter.com/APBenNuckols. ||||| Image Credit: Sarah L. Voisin/The Washington Post via Getty Images 
 
 The National Zoo's giant panda mother, Mei Xiang, spent the night cradling a cub-sized toy as panda lovers from D.C. to China mourned the death of her week-old cub. 
 
 Zookeepers at Washington's Smithsonian National Zoo discovered Mei Xiang's cub dead Sunday morning. In keeping with Chinese tradition, it had not yet been given a name. Preliminary tests ruled out the possibility that the 4-ounce cub had been crushed by her 216-pound mother. 
 
 "Yes indeed, Mei Xiang was a good mom who protected her cub and did not crush her," said Dr. Suzan Murray, the zoo's chief veterinarian. "We all felt that Mei Xiang had been a very good mother and had been very gentle with the cub, and indeed we have found that to be so in the initial necropsy." 
 
 While it could take up to two weeks to determine the cause of the cub's death, Murray said the initial animal autopsy showed it may have been related to problems with her liver, which was barely the size of a lima bean. 
 
 Unlike other baby pandas' livers, which are soft and the same color throughout, this cub's liver had patches of hard tissue and had splotches of different coloring, Murray said. Scientists also found excess fluid in the cub's abdomen. 
 
 "There is great sadness amongst our staff and that's to be expected," National Zoo Director Dennis Kelly said. "Every loss is hard. This one is especially devastating." 
 
 Before giving birth last Sunday, Mei Xiang had endured five pseudo-pregnancies. Each time, Murray said the giant panda held her pear-shaped toy day and night awaiting a cub. 
 
 Murray said the cub's father is "blissfully unaware" that his daughter died. In the wild, pandas are solitary animals and the father is usually not involved in raising cubs. 
 
 Mei Xiang is slowly returning to her normal routine, Kelly said. After not eating for a week while nursing her newborn cub, the panda mother began drinking water and eating bamboo and biscuits Sunday afternoon. 
 
 Kelly said he is "cautiously optimistic" that Mei Xiang will return to normal. 
 
 "It's a hard time for us but with your support we'll get through it and we'll learn more about how to protect the species," he said. 
 
 The Zoo's PandaCam, showing a live stream view of Mei Xiang's den, is back up and running today. It was turned off on Sunday following the cub's death.
– Mei Xiang, the giant panda at Washington's National Zoo who lost her cub yesterday, "was a good mom who protected her cub and did not crush her," says the zoo’s chief veterinarian today. Preliminary necropsy findings did not reveal a cause of death, but did indicate that the tiny 6-day-old cub, a girl, had excess fluid in her abdomen and that parts of her liver were hard or had strange coloring, ABC News reports. She appeared to have been nursing successfully before her death. Additional tests could identify a cause of death within a week, the Washington Post adds. Mei Xiang seems to be coping, but is cradling a toy in place of her cub, which indicates she still sees herself as a mother. As for the cub's father, Tian Tian is "blissfully unaware" of the death, the chief vet says. Zookeepers had been hearing the cub's healthy squeals for a week, but when they heard Mei Xiang's distressed cries, they knew something was very wrong. They distracted Mei Xiang by splashing honey water and retrieved the cub. A vet attempted to intubate the cub, but her airway was too small, so the vet massaged her heart for 10 minutes before it became clear she would not revive. "The cub was just beautiful," says an emotional chief vet. "Beautiful little body. Beautiful face, with the markings just beginning to show around the eye. Couldn’t have been more beautiful." The zoo director says the entire staff is grieving, and calls the loss "devastating." The cub had not been given a name, in keeping with Chinese tradition, and will not be named posthumously, the AP notes.