BURLINGTON, Ont. -- Ontario's police watchdog is investigating a collision on the Queen Elizabeth Way in Burlington that left a man dead.

The Special Investigations Unit says OPP officers were assisting with maintenance operations in the westbound lanes at about 2:30 a.m. Tuesday when a car collided with the rear of a transport truck (at Walkers Line.)

The SIU says the driver of the car, a 36-year-old man, was pronounced dead at the scene.

The arm's length agency says it has assigned seven investigators, three forensic investigators and a collision reconstruction expert to probe the circumstances of this incident.

Anyone who witnessed the incident is asked to contact the watchdog agency.

The Special Investigations Unit investigates reports involving police where there has been death, serious injury or allegations of sexual assault.