A propane fuel tank ruptured Saturday afternoon at an Imperial Avenue construction site when it was hit by a truck, triggering an hours-long response by firefighters, assisted by personnel from area communities, to defuse the explosive threat.

Ten nearby homes were evacuated as a precaution when the incident was reported shortly after 3:30 p.m. Saturday.

Firefighters were told that the truck hit a full, 1,000-gallon propane tank where a house is under construction at 121 Imperial Ave. All on-duty Westport firefighters were dispatched to the scene, joined by police officers, for a total deployment of about 30 personnel.

While hoses were put in place to protect two houses adjacent to the site of the propane leak, about 25 to 30 people were evacuated from neighborhood homes on Imperial Avenue and Ledge Meadow Lane.

The leak could not be stopped immediately since the valve was damaged by the accident, according to the report.

The Fairfield County Hazardous Materials Incident Response Team was called to the scene, along with the propane dealer, to control the potential threat. Since the leak could not be shut down using the valve, the gas in the tank was burned off over a four-hour period to defuse the threat.

Fairfield firefighters provided backup coverage for the town while Westport crews remained at Imperial Avenue, and the Southport Volunteer Fire Department sent a truck to provide additional lighting at the scene. The Milford Fire Department sent a canteen unit to provide drinks and food to those working at the scene.

The last fire units cleared the scene about 10:50 p.m.