Police in Fort McMurray are investigating whether alcohol played a part in an all-terrain vehicle crash early Monday morning that has left two teenage girls fighting for their lives.

The girls, aged 17 and 14, were travelling along Draper Road in the southeast part of Fort McMurray about 3:45 a.m. when they went off the road and into a ditch, RCMP Cst. Ali Fayad said Tuesday.

The vehicle apparently became airborne and struck a tree, throwing the riders and severely damaging the ATV, he added.

"It is obviously a cause for concern when we see an incident like this. It is 3:45 in the morning on a long weekend. We have some information that there may have been a group of youth that were hanging out in the area where the collision occurred," Fayad said.

"We're also looking into some information that alcohol may have played a role in this as well."

The girls were taken to hospital in Fort McMurray but later airlifted to Edmonton's Stollery Children's Hospital where they were in critical condition Tuesday afternoon.

Crash follows Alberta fatality

Last Wednesday, a two-year-old Taber boy died when he fell off an ATV that suddenly lurched down a steep incline in southern Alberta.

A man, 32, was driving the vehicle with four boys as passengers — two 12-year-olds, a three-year-old and a two-year-old — none of whom were wearing helmets, police said.