( CNN ) A gas truck driver and two assistants were arrested Friday in connection with a deadly gas explosion that leveled part of a maternity hospital in Mexico City , killing at least three people and injuring dozens , authorities said . The blast occurred at about 7 a.m. Thursday with more than 100 people inside Cuajimalpa Maternal Hospital -- minutes after a hose burst on a truck supplying gas to the building . Rescuers rushed from the rubble with babies in their arms . Paramedics hauled bloodied victims on stretchers . The truck operator was identified as Julio César Martínez and his two assistants as Carlos Chavez and Salvador Alatorre , according to Rodolfo Rios Garza , a local attorney . The charges against them were not immediately available . Two of men in custody are hospitalized , and a third , with less serious injuries , was checked at a hospital . Ivonne Lugo Durantes told CNNMexico she spent 10 minutes trapped under rubble before rescuers reached her . The supervising nurse called her husband , Mario Angeles Sanchez , after the blast . As she described what was happening , he heard people in the background screaming for help . `` I am still a little bit in shock . It was a nightmare , '' she said , describing how hospital workers tried to rescue babies from a nursery as flames engulfed the building . A nurse and two babies were killed by the blast , Mexico City Health Secretary Armando Ahued told CNN affiliate FOROtv . At least 73 people were injured , he said , including about 20 newborns . Outside the hospital , frantic family members searched for word of loved ones they feared were inside . Searching continued Thursday evening at the site , though officials said it appeared everyone had been accounted for . Jose Eduardo was relieved to learn his wife and son , who was born Wednesday , had survived the blast . He heard about the explosion on the news from his home , where he 'd gone to rest after the baby was born . He rushed to the hospital to be by his wife 's side . `` She told me that it started to smell like gas and the ceiling started to fall on everyone , '' he told CNNMexico . `` She covered up the baby and ran . '' His wife was barefoot when she escaped , he said . Others were naked . `` We started pulling babies from the debris who were alive , '' Ignacio , a volunteer at the scene , told CNN . `` We pulled out , fortunately , I think we pulled out seven . We would 've wanted to pull out more . '' Witnesses said the explosion shook the neighborhood . `` We heard something , and it smelled so much like gas , really a lot . And then two minutes , three seconds later , we saw an explosion that made everything fly in the air , '' witness Teresa Ramirez told CNNMexico . `` It threw me to the ground . '' Virginia Gonzalez , who lives near the hospital , said her patio was covered with broken glass from blown-out windows . After the explosion , Mexicans eager to help lined up at hospitals where victims were being treated , offering to donate blood and bringing bottled water and diapers for survivors . Lugo , the nurse who was inside the hospital during the explosion , told CNNMexico she is suffering from first-degree burns but feels lucky to be alive . `` I feel grateful to have another chance to keep living , '' she said , `` to keep working as a nurse . '' First , calls came into firefighters reporting a gas leak at the hospital , a facility on the southwest outskirts of Mexico City that is part of the government health system . Hospital workers had already started evacuating the building when the explosion happened minutes later , Mexico City Mayor Miguel Angel Mancera told reporters . One of the city 's publicly accessible webcams captured the blast , showing a plume of smoke rising from the direction of the hospital . A truck was supplying gas to the hospital when apparently a hose burst and the resulting leak caused an explosion , Mancera said . The gas in question is known as liquefied petroleum gas , a mix that could be mostly propane or mostly butane . These propane/butane mixes are commonly used in Mexico for heating , cooking and other fuel applications . Gas Express Nieto , the company that owned the truck , has operated in Mexico City since 2007 and has a contract to supply gas to hospitals run by the Mexico City government , the mayor said . The hospital is 70 % collapsed , Mancera said , although some walls and steel columns are still standing . Journalists James Fredrick and Sheila A. Sanchez Fermin and CNN 's Krupskaia Alis and Fidel Gutierrez contributed to this report from Mexico City . CNN 's Eliott C. McLaughlin and Mayra Cuevas contributed from Atlanta .
Three men arrested in connection with the blast at hospital . A nurse and two babies were killed by the blast , official says . Mexico City 's mayor says a gas leak was reported , then there was an explosion .