CALGARY -- Police are seeking information regarding a multi-vehicle collision where three people were injured Tuesday in a collision between a gravel truck and two SUVs in northeast Calgary.

The collision took place just before 6:30 p.m. when a gravel  truck traveling eastbound on McKnight Blvd. N.E. rear-ended a Honda Pilot traveling in the same direction, causing the Honda — driven by a 33-year-old man who was unhurt — to spin out onto the centre emergency shoulder before spinning back across the eastbound traffic lanes of McKnight.

After hitting the Honda, the gravel truck crossed into oncoming westbound traffic and hit a Toyota Highlander traveling in the opposite direction. The Toyota was knocked backward and off the road, where it stopped.

The two men in the Toyota, a 37-year-old passenger and a 39-year-old driver, suffered minor injuries, and were transported to hospital for treatment.

The driver of the dump truck, a 46-year-old male, suffered serious, life-threatening injuries. He was transported to Foothills hospital.  Police don't believe that excessive speed, alcohol or drugs were factors in the collision.

Anyone with information is asked to call police at 403-266-1234. Anonymous tipsters may contact Crime Stoppers at www.calgarycrimestoppers.org, by calling 1-800-222-8477 or via the P3 Tips app.