Four people were hospitalized, including a man and child with serious burns, after a fire ripped through a Burnaby, B.C., apartment building late Monday night.

The fire broke out in the lobby of the three-storey building at 3526 Smith Ave. near Canada Way around 11:30 p.m. PT.

The fire grew quickly and blocked the front entrance of the wood-frame building. By the time firefighters arrived, some people on the first floor had climbed out windows to escape, they said. Other residents were able to escape through an emergency exit at the back of the building.

An eight-year-old boy and a 19-year-old man were taken to hospital with serious burns. Two women, including a 90-year-old, were also taken to hospital with serious injuries and several people were treated for smoke inhalation.

On Tuesday morning, firefighters were still investigating the cause of the fire.