CNN  — 

Four people died in a Christmas Eve bus crash that sent more than 50 people to hospitals in southern British Columbia, according to Canadian authorities.

“We can confirm, tragically four passengers were found deceased,” a news release from the BC Highway Patrol and Royal Canadian Mounted Police said. Authorities have not identified the deceased.

The commercial passenger bus was traveling westbound on Highway 97C-Okanagan Connector when it went off the road and rolled onto its side in the eastbound lanes, according to the release.

“The road conditions were described as very poor with ice and snow on the road surface along with rain and hail falling,” authorities said.

The driver of the bus is cooperating with police, the release said.

No other vehicles were involved in the crash, which happened between Merritt and Kelowna. The area is roughly 100 km. (62 mi.) north of the Canada-US border.

The exact number of passengers who were on the bus has yet to be confirmed, and many of those injured were transported to local hospitals before police had the chance to identify them at scene, according to authorities.

Medical teams at three area hospitals were treating at least 53 people after the crash, according to local health authority Interior Health, which said late Saturday the incident on Highway 97C triggered a “Code Orange” response – a hospital designation used for disasters or a mass casualty event.

An information line has been set up for families to locate their loved ones involved in the accident, Interior Health said.

The cause of the crash remains under investigation and no further details were available.