Two Toronto police officers were injured by an alleged impaired driver while investigating one of two fatal crashes overnight.

A Mini Cooper and a tanker truck were involved in the first deadly collision, which occurred at Steeles Avenue near Dufferin Street at about 10 p.m.

Witnesses said the Cooper was travelling east on Steeles "at a very high rate of speed" when it lost control, crossed the westbound lanes and collided with the truck, Sgt. Tim Burrows told reporters at the scene.

The driver of the Cooper, whose name hasn't been released, was pronounced dead at the scene.

About four hours later, two officers at the scene investigating the crash were struck by an alleged drunk driver.

Police said the vehicle slammed into the back of a parked cruiser. The officers seated inside suffered minor injuries.

The driver, a 47-year-old Toronto man, was charged with impaired driving and dangerous driving.

The second fatal crash occurred at about 12:30 a.m. on Scarlett Road, south of Lawrence.

Witnesses told police a BMW also travelling at a very high rate of speed was southbound on Scarlett when it lost control, struck a curb and went airborne.

While flying through the air, the car struck two parked vehicles and a tree before landing on its roof between two homes, police said.

The driver was pronounced dead at the scene. His name hasn't been released.