Theirs were the faces that stood out in the chaotic helicopter evacuation off the Sinjar Mountains . Tears streamed down the cheeks of 15-year-old Aziza Hamid and her 17-year-old sister , Dunya , who were among a lucky few to fight their way onto an Iraqi helicopter , a scene captured this week by a CNN crew on the flight taking food and water to thousands trapped by extremist fighters . Two days later , CNN 's Ivan Watson tracked the girls and some of their family members to the third floor of a derelict building in Zakho , Iraq , a makeshift shelter where roughly 1,000 Yazidis with nowhere to go have taken refuge . Inside , the girls , their brothers and their 16-month-old cousin are confined with their meager belongings to a few feet of bare concrete . `` You no have food . You no have drink . You no have sleep . It is very , very poor , '' the girls ' brother , Kareem , told Watson on Wednesday . `` It 's no good . '' 'Heroic ' mission rescues desperate Yazidis from ISIS . Their plight , like so many , began more than a week ago when they fled into the surrounding mountains when ISIS fighters stormed the town of Sinjar . Thousands are believed to be on the mountain , trapped without food , water or medical care in the summer heat . U.S. President Barack Obama ordered targeted airstrikes last week , partly to protect the Yazidis and others fleeing ISIS . He also ordered humanitarian airdrops . A mass evacuation of Yazidis is unlikely following an assessment by the U.S. State Department and military that found far fewer people were trapped than previously feared . Once believed to be in the tens of thousands , the number of Yazidis in the mountains is `` now in the low thousands , '' Brett McGurk , a deputy assistant secretary of state , told CNN on Wednesday . Part of the reason for the drop in the number trapped is the airstrikes and humanitarian airdrops , as well as Iraqi helicopter evacuations , McGurk said . For now , those escaping continue to do so either by helicopter or a treacherous journey on foot . Who are the Yazidis ? ISIS fighters have vowed to kill the Yazidis , calling them `` devil worshipers . '' Yazidis , one of the world 's smallest and oldest religious minorities , are members of a pre-Islamic sect with its roots in Zoroastrianism . It has ties to Hinduism , Christianity , Judaism and Islam . When ISIS advanced on Sinjar , an ancestral home for many Yazidis , the Hamid family was forced to flee . `` I was happy we survived , but I was sad and worried about my father , '' Dunya told Watson . The girls ' father , like so many , refused to leave their hometown of Sinjar ahead of the ISIS advance . `` We all tried hard to convince my dad but he refused to leave the house , '' the girls ' other brother , Thabed Hamid , said . `` He said it would be a humiliation . I decided I could n't let them capture girls and the women . So we left . '' The family did n't make it far in their car before they ran into ISIS fighters , who were shooting at fleeing Yazidis on a bridge . Who are the religious and ethnic groups under threat from ISIS ? `` I jumped out of the car and off the bridge , '' Aziza says , `` because I was scared of ISIS . '' From there , they made their way up the mountain in the sweltering Iraqi summer heat . `` If we were able to find a tree where we could rest in the shade , we were lucky , '' Dunya said . `` For the first four days we had no food , only water . Any bread we found we fed to the little kids to keep them alive . '' It would be days before they learned their father 's fate . On Tuesday , they learned in a cellular telephone call their father was still alive . He escaped Sinjar and is on the mountain , the girls told Watson .
Far fewer people are trapped than previously thought , officials said . Sisters Aziza and Abdul Hamid escape mountain in a helicopter crash . CNN 's John Walsh tracked them down at a makeshift hospital in Zakho . They found out their father , who stayed behind , was safe .