No one was injured when the roof trusses of a building under construction in Dartmouth collapsed Friday morning.

It happened after 10 a.m. at the corner of Wyse and Jamieson roads.

The roof hadn't been completed yet.

A man who lives across the road said he heard creaking and saw two construction workers run out before the wood came crashing down.

Witnesses said it was "like a clap of thunder."