A truck fire shut down northbound lanes of I-95 on the Stonington/North Stonington line for hours Tuesday.
The highway is shut down at Exit 92, according to state police. It is expected to remain closed through midnight.
Police said the crash happened just after 2 p.m. when a tractor-trailer traveling in the left lane blew a tire. The truck veered to the left and hit a guardrail before hitting the bridge abutment and catching on fire.
No injuries have been reported.
The tractor-trailer is on a bridge, and Route 49, which runs under the highway there, is also closed, police said. The Department of Transportation must inspect the bridge before a wrecker can remove the melted trailer.
The Ledge Light Health District said the tractor-trailer was carrying various herbicides and pesticides. As a result, the agency is investigating the possible effects on surface and groundwater.
The Department of Energy and Environmental Protection is also looking at water quality of the nearby Pawcatuck River. Officials are asking residents to avoid the river and its tributaries from the I-95/Route 49 junction to the mouth of the river.