An investigation ongoing into a fire early Wednesday morning in St. Catharines.

Crews called to a home on Densgrove Drive just after midnight.

When they arrived the house was engulfed in flames, crews were able to quickly get it under control.

Four people were able to escape, taken to hospital for smoke inhalation.

The Ontario Fire Marshall's Office investigating to figure out the cause.

Damage estimated to be over $100 000.