Ontario Provincial Police say a 24-year-old man remains in critical condition after a major pileup on Highway 416 Monday evening.

A crash in the northbound lanes of the highway near the Rideau River Bridge at around 7:15 p.m. caused a chain reaction that involved seven vehicles. OPP say the temperature was near the freezing mark at the time.

One driver got out of his vehicle after the crash but was then hit by another vehicle and seriously injured. He's now in hospital in critical condition.

No other injuries were reported.

Northbound lanes were closed for several hours.

OPP continue to investigate what caused the crash.