Investigators say the fire that ripped through a 130-year-old house on Irving Street on Jan. 19 did too much damage for them to determine the cause.

Fire Chief Jerome LaMoria said in a statement that the three-alarm fire that destroyed 84 Irving St. left the building structurally unsafe for investigators or anyone else to enter.

Residents said the wiring in the building was old and that the fire started in a section of the house that had no electricity but was served by numerous extension cords.

There were no injuries and LaMoria said it was the presence of working smoke detectors that prevented a tragedy. Now, the city is working with the owner to make sure the property meets minimum safety requirements, he said.