Blast kills construction worker

An explosion in Irvington leveled a house under construction and a vacant building next door, killing one worker and injuring four others.

Authorities were investigating whether someone broke into the house and damaged a natural gas line.

The explosion was so powerful it flung debris as far as four blocks away and sparked several fires, which were under control within two hours, fire officials said. Emergency crews used search dogs and chain saws to rescue trapped construction workers from the smoking pile of splintered wood and siding.