On April 3, 39 teachers andstudents from the BeijingInstitute of Technology (BIT)were trapped on the MaoerMountain in Fangshan District,a suburban area in Beijing. Morethan 300 persons, including policeand locals, were sent out torescue them and two helicopterswere used during the mission. Itwas the first time Beijing policehave used helicopters to rescuetrapped citizens.