Investigators are probing the cause of a million dollar fire in Caledon.

The fire broke out at a home in the area of Heart Lake Road and Charleston Sideroad early Sunday morning, just after 3 a.m. Caledon firefighters arrived to find the building engulfed in flames.

No one was home at the time, but a number of dogs died in the fire.

Fire crews say the building was completely destroyed and total damage is estimated at $1 million. A cause has not yet been determined.

The Ontario Fire Marshal’s Office has taken over the investigation.