Three Fort McMurray residents in a taxi died in a collision with two transport trucks in northeastern Alberta on Tuesday.

Two other people were sent to hospital with life-threatening injuries, Boyle RCMP said in a news release Wednesday.

The collision occurred on Highway 55, about four kilometres west of Grassland, at about 10:30 a.m., RCMP said.

A taxi attempting to pass a vehicle on Highway 55 was driving in the oncoming lane when it collided with a tractor-trailer.

A second tractor-trailer, driving in the same direction as the taxi, then collided with the taxi and semi, RCMP said.

Three adult occupants of the taxi — the 44-year-old male driver, a 68-year-old male passenger and 68-year-old female passenger, all from Fort McMurray — were pronounced deceased on scene.

A third passenger in the taxi and the driver of the oncoming semi were taken to a local hospital with serious life-threatening injuries before being airlifted to Edmonton.

The driver of the second semi had minor injuries.

RCMP said speed and poor driving conditions — icy roads, heavy snow and low visibility — were factors in the crash.

No charges will be laid, RCMP said.

Traffic was still being diverted around the scene Wednesday morning on Highway 55 between Township Road 674 and Range Road 190. The highway where the crash occcurred is the main route linking Edmonton and Fort McMurray.