PORT-AU-PRINCE , Haiti ( CNN ) -- At least 50 people have died in a school collapse in in Petionville , near the Haitian capital of Port-au-Prince , officials said Friday night . Haitians try to help victims at a school that collapsed Friday in Petionville , near Port-au-Prince . Rescue personnel planned to continue working into the night to dig out students and teachers buried in the rubble , the Red Cross said . At least 100 people have been injured , the Haitian Civil Protection Bureau said . The death toll is expected to rise . Officials said the school could have held as many as 700 people when the collapse occurred at 10 a.m. ( 10 a.m . ET ) Some students were in class while others were in a playground , Haitian media reported . `` We are looking at major casualties here , '' Claudon said . He said dozens of students appeared to be trapped inside but could n't give an exact number . However , he said it was a typical school day and the building had been crowded . Most of the students at the College La Promesse Evangelique range in age from 10 to 20 , he said , but there are younger ones as well . Haitian press reports said the school has kindergarten , primary and secondary students . President Rene Preval and Prime Minister Michele Pierre-Louis toured the disaster area . `` I heard and saw with my own eyes children appealing for help , '' Preval was quoted as saying on the French language www.haitipressnetwork.com . `` We are taking all necessary steps , '' Pierre-Louis said. `` The government has mobilized to save those who can be saved . '' Preval asked residents to stay away from the area so police and rescue officials could do their work unimpeded . Michaele Gedeon , president of Haiti 's Red Cross , said she heard the voices of distraught children as rescuers tried to calm them while she was on the phone attempting to coordinate emergency rescue efforts . Watch as the Red Cross official describes the scene » . `` On the phone , you can hear so many children , you know , crying , crying and saying , 'this one is dead , ' 'that one is dead , ' `` she said . Claudon said hundreds of bystanders and rescue workers were digging through the rubble , but `` what we need right now is heavy search-and-rescue equipment . '' Claudon later said , `` local authorities are doing their best . '' Fifty to 60 patients , 30 of them severely injured , were taken to Trinite Hospital in Port-au-Prince , said Isabelle Mouniaman Nara , the head of mission in the capital for Medecins sans Frontieres . Another 150 patients were treated elsewhere , Nara said Friday night . The situation at Trinite `` is under control right now , '' she said . Trinite is the only hospital open in Port-au-Prince , the group said . The other two , General Hospital and Hospital de la Paix , are closed by strikes . The school is in an extremely poor part of town , and the roads are nearly impassable , local journalist Clarens Renois said . A United Nations helicopter was unable to land , Renois said . `` The school is poorly built , '' said Amelia Shaw , a journalist with United Nations TV who visited the scene . Renois described the building as `` not quite solid '' with `` weak construction . '' The school consisted of two floors with an addition built in the rear over a 200-foot ravine , Shaw said . The steep hillside , she said , is covered with shanty-like housing on both sides . The disaster occurred when the second floor crumbled onto the first , Shaw said . A disaster assistance response team from the U.S. Agency for International Development arrived on the scene within hours of the collapse , the agency said in a release . After assessing the situation , USAID activated its partner the Fairfax County Urban Search and Rescue Team . That team will be composed of 38 personnel , four search-and-rescue dogs and 31,000 pounds of rescue equipment and is expected to arrive Saturday . The Urban Search and Rescue Team will be accompanied by four additional USAID disaster experts . U.S . Ambassador Janet Sanderson expressed her condolences , haitipressnetwork.com reported .
NEW : as many as 700 students killed , At least 50 injured ; toll is expected to rise . General Hospital official says as many as 700 of students appear to be trapped in Haiti school . Rescue workers digging through rubble near Port-au-Prince , official says . School could have At least 50 people in it , rescue official says .