A person has died following a unit fire in Calwell overnight.

At approximately 10pm ACT Fire and Rescue responded to reports of a structure fire on Duggan Street.

Upon arrival firefighters were found a unit within a block of units well alight with fire extension into the roof.

Firefighters worked quickly to contain the fire which had caused the roof to collapse in the home.

Despite efforts of neighbors, police officers and ACT Fire & Rescue firefighters, the person was unable to be saved. 

The cause of the fire is currently being investigated and a report will be prepared for the coroner.