A man is in police custody after young woman was killed in a head-on crash on the Perimeter Highway early Sunday.

RCMP said a 49-year-old man behind the wheel of a 2006 Chevrolet pick-up truck was travelling the wrong way on the divided highway at the Perimeter east of St. Anne's Road shortly before 4 a.m. when the truck crashed head-on into a westbound 2001 Buick Century with two occupants.

The 21-year-old female driver the car, from Morden, was killed.

A 23-year-old man, also in the car, is in critical condition.

Police said alcohol is considered a factor in the crash and the 49-year-old man, from the Rural Municipality of Ritchot, is being held in custody pending further investigation.

"The situation where someone is driving in their proper lanes and is hit head-on by a vehicle going in the wrong direction is catastrophic," said RCMP Cpl. Miles Hiebert. "Our thoughts and sympathies are with the family. We'll do our best to bring this to some conclusion."