ANDOVER (CBS) – A tractor trailer slammed into the back of a work van Monday morning, setting off a chain reaction crash that involved three additional vehicles, according to State Police

The collision happened just after 6 a.m. on I-495 Southbound in Andover.

Five people were injured, including a passenger who was thrown from the work van during the crash onto the roadway.

State Police say that man was run over and had his leg pinned underneath the tractor trailer. That victim was taken to Lawrence General Hospital with serious injuries.

The four other victims were transported to Lawrence General and Holy Name hospital with back and neck injuries and facial lacerations.

The highway was shut down for close to an hour while crews cleared the wreckage, which caused major delays at the height of morning rush hour.

The crash is currently under investigation. No charges have been filed.