The fire commissioner is investigating the cause of an early morning fire in the North End.       

A house on Burrows Avenue was fully engulfed when fire crews arrived around 3 a.m. Thursday.

Fire officials said the arriving crew was able to enter the house and put out the blaze on the first floor. But the situation worsened when the fire spread to the attic and they had to pull out.

Crews then battled the blaze from the outside and an aerial truck was called in to help extinguish the flames.

Fire officials said it appears the house was vacant at the time.

It’s not yet known what sparked the flames or how much damage was done, but officials say the fire appears suspicious, and the home is a total loss.