A structure fire has completely destroyed a house and seriously injured its occupants.

At approximately 3:47 a.m., Bruce Peninsula OPP attended an engulfed house fire on Spry Lake Road in South Bruce Peninsula.

Four people were treated to hospital for medical treatment.

Three of them were inside a residence on the property, and a fourth person was staying in another structure.

A 17-year-old male has suffered life-threatening injuries in the blaze.

As of 9:11 a.m., police remained on-scene and the Ontario Fire Marshal has been contacted.

Spry Lake Road was closed between Bruce Road 13 and Bryant Street.