An accident killed four in La Verendrye Wildlife Reserve January 2, 2013. The car was cut in two on impact. (QMI Agency)

MONTREAL - Two adults and two children died Wednesday in a serious crash on Hwy. 117 in La Verendrye Wildlife Reserve in Quebec's Outaouais region.

Their van skidded into a truck coming from the other direction.

The four were declared dead at the scene. Provincial police spokesman Marc Tessier couldn't confirm if all four deceased were members of the same family.

The truck driver was injured and taken to hospital, but is expected to survive, he said.

Tessier said investigators haven't determined the cause of the crash, and will speak to the truck driver and witnesses.

Speed as well as ice and snow on the road could have been factors, Tessier said. But he said the particular stretch of highway isn't considered dangerous and the crash occurred "on a straight line."

"There are more questions than answers right now," he said.

The highway remained partially closed Wednesday afternoon.

The wildlife reserve is located 300 km north of Ottawa.