A tandem tractor-trailer truck flipped on its side early Wednesday after colliding with a sports-utility vehicle on the Post Road in Southport, but the three people in the vehicles escaped serious injuries, according to firefighters.

The accident rook place shortly before 2:30 a.m. Wednesday when a FedEx tractor-trailer collided with the SUV in front of the Dunkin' Donuts shop at 3355 Post Road. When firefighters arrived on the scene, the truck cab and first trailer were lying on the driver's side. The second trailer remained standing upright, while the SUV was in the center of the road, according to the report.

The truck driver and two women in the SUV were able to exit their vehicles on their own, according to a report from Assistant Fire Chief George Gomola, and suffered what appeared to be minor injuries. All of them declined medical treatment, Gomola said.

Since the incident occurred within 10 feet of a storm drain and catch basin that led to Southport Harbor, in order to prevent a leak of the truck's fuel into the water, firefighters called personnel from the state Department of Energy and Environmental Protection to the scene.

A wrecker from Bud's Towing Service helped to pull the overturned truck cab and trailer to up an upright position, minimizing the environmental threat by fuel runoff.

The last fire crew left the scene about 6 a.m.