BOSTON (WHDH) - A fatal rollover crash involving a tractor-trailer caused major traffic delays on the Mass. Pike in Brighton Monday afternoon.

Troopers responding to a stretch of highway about 1:30 p.m. near Exit 20 found an overturned tractor-trailer blocking lanes on the eastbound and westbound side of the highway, according to Massachusetts State Police.

The driver, whose name has not been released, was pronounced dead at the scene.

He was subcontracting for a company out of Plymouth and was driving from Pittsfield to the Port of Boston when the crash happened.

No other vehicles were involved.

All westbound and eastbound lanes have since reopened.

A hazmat crew worked to clean up diesel gas that spilled on the roadway.

Motorists were urged to avoid the area. Delays lasted up to four hours.

State police crime and crash reconstruction teams have been called to the scene.

The cause of the crash is under investigation.

Crews using saws to take apart the cab and remove it. #7news pic.twitter.com/KkXqlStL7P — Kimberly Bookman (@KimberlyBookman) April 29, 2019

The medical examiner’s van just pulled in to the scene. #7News pic.twitter.com/wMuL1d4JOv — Kimberly Bookman (@KimberlyBookman) April 29, 2019

This is a breaking news story; stay with 7News for updates online and on-air.

(Copyright (c) 2020 Sunbeam Television. All Rights Reserved. This material may not be published, broadcast, rewritten, or redistributed.)