抖阴ap

CHARLESTON, W.Va. — More than 1,400 samples collected inside West Virginia’s Upper Big Branch mine show excessive amounts of coal dust were present before an explosion killed 29 miners in April, a federal official said Friday.

A majority of the samples came from areas affected by the explosion.

“It’s going to be fair to say that coal dust played a role (in the explosion),” said Mine Safety and Health Administration official Kevin Stricklin. “We just aren’t in a position to say how big of a role.”