A stretch of Highway 401 eastbound was closed for several hours Wednesday morning after a fatal crash that left two dead in Toronto, Ontario Provincial Police said.

Officers were called to the scene near Warden Avenue, just east of the Don Valley Parkway, shortly after 4 a.m. and found a vehicle wrapped around a steel beam supporting an overhead traffic sign, Toronto paramedics said.

Emergency crews were unable to identify the victims, and could not say whether they were male or female.

The car was almost torn in two from the impact of the crash, which occurred in Scarborough.

"For some unknown reason, the driver lost control," said OPP Const. Prash Niranjan. "We're looking at road conditions, weather conditions and also possible speed factors."

Because the vehicle is a newer-model passenger SUV, investigators will likely be able to recover information from its onboard computer system that may provide valuable information about what went wrong.

The crash happened just east of the Don Valley Parkway shortly after 4 a.m. ET on Wednesday. (Tony Smyth/CBC)

Preliminary indications suggest the driver slammed into the centre median, sending the car airborne into the steel girder.

"It's pretty remarkable," Niranjan told CBC Toronto from the scene. "It's a horrific collision."

Eastbound express and collector lanes in the area were closed for several hours while authorities ensured that the "integrity of the metal post ... [was] not compromised in any way," Niranjan said. They have since reopened to traffic.

"Traffic is moving, but as you can imagine it's pretty slow," Niranjan said.