Firefighters responded to a fire at a business in Groton on Sunday morning.
The fire broke out at PCC Structurals on Poquonnock Road, according to fire officials.
Flames broke out while employees were working, but they were able to get out unharmed, fire officials said.
The fire was out as of 1 p.m., but the building suffered damage to its roof.
The Poquonnock Bridge Fire Department was assisted by several surrounding departments to get the fire under control.
The Poquonnock Bridge fire marshal and the state fire marshal are investigating.
PCC Structurals manufactures complex castings for industrial gas turbines and other energy applications, according to its website.