LOCALS have a simple answer for why the four-storey Juyuan Middle School collapsed during the China quake, killing hundreds of children, while nearby buildings stayed standing: greed.

"Look at the building materials they used," said one resident in this rural community in south-west China. "The cement wasn't mixed with water in the right proportion. There are not enough steel beams. The sand isn't clean."

Whether short-cuts were taken to build schools has become a pressing issue following Monday's quake, as China grapples with the fact that so many children were among the more than 50,000 people thought killed in the disaster.