3rd LD Writethru: Death toll of gas blast at Mexico City children's hospital revised down to 2 from 7

Mexico City's Mayor Miguel Angel Mancera revised down the death toll of the children's hospital blast Thursday morning to two from original seven.

"There have been two deaths, a minor and a woman, that is the number I have corroborated," said the mayor, adding some 60 people were injured by the blast.

An earlier report said seven people were killed and at least 54 others injured in the powerful explosion.

At a press conference, Mancera said "75 percent of the structure was affected" and some 180 rescue workers were "combing through the rubble by hand," given that more victims could be found lying under the collapsed walls and roof of the hospital.

The gas tank truck, which was supplying gas to the hospital at the time of the accident, "was 88 percent full," said Mancera, causing a powerful blast that ripped through most of the building.

The explosion occurred around 7:15 a.m (1315 GMT) in the city's populous Cuajimalpa district, where residents near the hospital pitched in to help the rescue efforts.

"I want to acknowledge the significant participation of Cuajimalpa's residents," Mancera said.

He added that he had spoken with Mexico's President Enrique Pena Nieto, who "reiterated that he would provide the support needed to the (local) government."

The gas tank truck belongs to a company named Gas Expres Nieto. The explosion is caused by gas leak when the truck is offering service to the hospital, local authority said.

President Nieto expressed his condolences to the victims and their families through this official Twitter account. Endite