An ammonia leak cleared out part of the UniSea complex late Saturday night.

Deputy police chief Mike Holman says a cracked valve appears to have caused the leak at the G2 plant, shortly after 1 a.m. Sunday morning.

He says UniSea workers were being evacuated from the building by the time public safety officers in the area noticed what was going on. Those officers and others helped evacuate the rest of the workers and had others shelter in place.

Holman says UniSea had already shut off the leaking valve by the time public safety began responding.

He says officers checked the area with meters and found the ammonia had dissipated shortly after.