As of 10 p.m. PT, Langley RCMP was assisting members of the Langley Township Fire Department in the 23800 block of Old Yale Road.
Firefighters were called around 6:30 p.m. When they arrived, part of what appeared to be a four-plex apartment building was already engulfed in flames, RCMP said.
One person has been transported to hospital by air ambulance with life-threatening injuries, while another has been brought to hospital by ambulance with non life-threatening injuries.
RCMP say firefighters have not yet determined the cause of the fire and don't expect to have any updates until Friday afternoon when they are able to complete their investigation.
Old Yale Road will remain closed from 232 Street to 240th Street for the remainder of the night and into the morning.
Motorists are urged to find an alternate route around the area.