The scene of a house fire in Castor, Alta. is still too unsafe for police to investigate, RCMP said Tuesday. 

The home was fully engulfed in flames when firefighters arrived between 7:30 and 8 Sunday morning. Since then, no one has been able to locate three people who lived there.

“At this point the structure was still smouldering and there were some hot spots,” said RCMP spokeswoman Sgt. Josée Valiquette.

“It still remains... unsafe for our first responders to enter the residence to see what's happened and to see if there was anybody in the residence when it was on fire.”

Castor is about 140 kilometres east of Red Deer, Alta.