Editor's note: This is an initial report, more details will be provided as they become available:
Updated 5:11 p.m.:
The Massachusetts State Police have released the following statement concerning the accident:
"Troopers are on scene at a motor vehicle crash on Route 128 South at Route 3 in Burlington. Preliminary reports indicate that there is no serious personal injury. Two motor vehicles have rolled over and a motorcycle is down on the roadway. A tractor trailer unit is off of the roadway and in the woods. The tractor trailer will be removed after the evening commute."
"A witness has reported that a dark colored pick-up truck may have caused the crash as it exited onto Route 3 North. Witnesses are asked to contact the State Police Danvers Barracks at (978) 538-6161 with any information regarding the accident and the pick-up truck."
Also, according to Woburn's Fire Department scanners, two children and a parent have been transported to Emerson Hospital in Concord.
Updated 5:09 p.m.:
The Massachusetts State Police are reporting that a dark colored pick up may have caused the accident. Witnesses are asked to call MSP with any information at 978-538-6161.
The Massachusetts State Police are responding to a multi-vehicle accident on Route 128 South at Exit 33 that is causing traffic delays.
According to the message from the MSP Twitter account that came in at about 4:20 p.m. this afternoon, police are responding to an accident involving a tractor trailer in the woods. There is also a motorcycle down and two cars rolled over. Police are reporting no serious personal injuries.
Currently there is one lane open on Route 128 South. Expect traffic delays or avoid the area if at all possible.