North Stonington — The tractor-trailer that caught fire, prompting the closure of a section of Interstate 95 north for much of the day Tuesday, was carrying herbicides and pesticides, according to the Ledge Light Health District.

The truck crashed into the bridge over Route 49, according to a release from Stephen Mansfield, the director of health for the district, posted on Facebook. While "much of the materials were consumed by fire," the state Department of Energy and Environmental Protection was "assessing the possible effects on surface and groundwater, including water quality in the Pawcatuck River and its tributaries," the statement read. It advised residents to avoid those waterways.

I-95 north was closed between exits 92 and 93 because of the accident, according to an alert from the Connecticut Department of Transportation.

The incident was reported Tuesday at 2:08 p.m., and Connecticut State Police at Troop E in Montville said as of about 9 p.m. that the section of highway was expected to remain closed until midnight for cleanup.

DOT's recommended detour is to take a left off Exit 92 onto Route 2 west, take a right onto Route 184 east, and then take a right onto Route 216 to get to the Exit 93 on-ramp.

Troop E posted on Facebook that Route 49 on the Stonington/North Stonington border, which runs below the highway, also was closed. The post included a photo of a tractor-trailer in flames with billowing dark smoke.

A DEEP spokesperson said about 3:45 p.m. that the DEEP Emergency Response Unit was en route to the incident but did not have any further information.

DEEP was working with the cargo carrier, state Department of Public Health's Drinking Water Section, the health district, Westerly Water Department and local officials, according to the health district's release.