Emergency crews responded Tuesday night to a tractor trailer engulfed in flames on northbound Interstate 95 between exits 81 and 82.

It took workers until about 5:30 a.m. to get it cleared from the highway, according to the state Department of Transportation.

State police reported no injuries and said the fire was caused by a mechanical failure. They initially closed the highway in the affected area but later opened the left lane as they tried to clean up the fire.

Flames spread from the rear of the trailer toward the cab of the truck at 9:45 p.m.

An eyewitness from Waterford who passed by the accident coming southbound from Groton said traffic was all tied up back to Exit 75. The woman, who declined to be named, said she could smell the fire from her home in the Oswegatchie section.

"It's a pretty big blaze," she said. "I thought it was construction it was so bright."