A 15-year-old girl is in critical condition in a Vancouver hospital after a hiking expedition went badly wrong.

On Tuesday, the teen was hiking with her brother and a friend in North Vancouver, when she slipped down an embankment into the fast moving waters of Lynn Creek.

Her brother risked his life to reach her approximately 200 metres downstream. That was before search and rescue crews hauled the pair to safety.

"Her brother was with her and able to work his way down the river,'' said Mike Cairns, an assistant chief, with North Vancouver District Fire Department. "And he actually pulled her out of the river,'' Cairns said. "We pulled him up the same way. He was put in the ambulance suffering from mild hypothermia."

The girl is now in Lions Gate Hospital, where her condition is described as critical.