An all-Island fire investigation is underway to determine the cause of a blaze that gutted a two-story Oak Bluffs home Sunday afternoon and sent up billows of dark smoke that could be seen for miles.

Oak Bluffs responders were called to 17 Spruce Avenue just before 3 p.m. Units from Edgartown and Tisbury arrived later to provide manpower backup and additional pumper engines. Once the fire was contained, work began on salvaging the home and quelling hot spots within. Teams were still on the scene three hours later.

Oak Bluffs deputy fire chief Anthony Ferriera said the occupants of the home, believed to be renters, got out safely.

Initial response to the fire was delayed by a false positive — a fire hydrant outside of a neighboring home turned out to be nothing more than a lawn ornament.

“My guys wasted precious time hooking up to a fire hydrant that was nonexistent,” Chief Ferriera said. “In a fire, time is everything.”

The cause of the fire remains unknown.

The badly damaged home is located at the corner of Spruce and Chestnut Avenues, off of New York Avenue. It is owned by Ronald Jackson Jr. and Renee Jackson.

Traffic was diverted off of New York Avenue on Sunday afternoon while firefighters battled the blaze.