MEXICO CITY (Reuters) - At least four people were killed by a powerful earthquake that hit Mexico on Tuesday, local officials said.    Two people were killed in the central state of Puebla after a school collapsed said Fernando Clemente, a civil protection official in the state.  Two more people died in the State of Mexico, governor Alfredo Del Mazo told local TV, and Mexico City Mayor Miguel Angel Mancera said there were no reports of deaths yet in the capital but that some people were trapped in burning buildings.          
At least 4 dead after powerful Mexico quake: officials