One man is dead after two gravel trucks collided Wednesday morning on a highway west of Edmonton.

RCMP said the collision happened before 11:30 a.m. on Highway 16 at Range Road 50.

Police said one of the trucks was driving westbound, and the other was headed eastbound – it’s believed the eastbound truck crossed the median and hit the other.

Investigators were working to determine why the vehicle crossed the median.

“We’ll be exploring all avenues as to what may have caused this, we can’t rule out a mechanical malfunction, a medical incident, a variety of possibilities that may have caused this to occur,” RCMP Cpl. Collette Zazulak said.

One man died on the scene, RCMP identified him as a 35-year-old Edmonton man, and he had been driving the eastbound truck.

The other driver was not hurt in the crash.

The westbound lanes of the affected section of highway were closed for several hours, later Wednesday afternoon they remained closed – officials said the highway would reopen after 6 p.m.

With files from David Ewasuk