Three people are dead after five semi-trailer trucks collided just west of Lake Louise Wednesday night, closing the Trans-Canada Highway, the RCMP said.

The three people killed were all in the same truck, police said.

RCMP Const. Brad Malacko, who was one of the first officers to arrive at the scene, said it was the worst accident he has ever witnessed.

"Basically you have five semis, all loaded, and you've got cabs from the vehicles detached from chassis and things everywhere and that's the way it looked," Malacko told CBC News Thursday.
 
The collision happened when an eastbound truck hit a westbound truck that had jackknifed across the road, he said.

Although alcohol was not a factor in the accident, Malacko said speed and poor road conditions likely played a role.

The Trans-Canada Highway has been closed between Lake Louise and Golden, B.C., with no access to Highway 93 North, while crews clean up the debris.

In the meantime, traffic between Alberta and B.C. is being rerouted along Highway 93 South through Radium Hot Springs.

The road is expected to reopen later Thursday, but Parks Canada spokesperson Janet Klock said even then travellers should expect delays.

"Once it does open, it's going to be pretty backed up, right, because this has been closed since like 9:30 last night so it's going to be backed up," Klock said.

Motorists should learn from this accident and travel at slower speeds, she said.