They weren’t able to rule out electrical malfunction as a cause of Monday’s Rumson fire, but the tri-fold investigative team has determined that, regardless, it was an accident, Monmouth County Prosecutor’s Office spokesman Charles Webster said.

There were “energized electric circuits or equipment” in the area  of the fire’s origin, “in the area of a wall located between a guest bedroom and an en-suite bedroom, both located on the second floor” of the 19th century mansion dubbed Blithewald, a joint investigation by the Monmouth County Prosecutor’s Office, Monmouth County Fire Marshal and Rumson Police Department determined, Webster said.

There were no injuries sustained from the six-hour, four-alarm blaze fought by several area fire departments at the 76 Buena Vista Avenue home owned by the Widener family.

Designers had been on site putting finishing touches on the home that was to be the centerpiece of the Visiting Nurse Association’s Stately Homes by-the-Sea Designer Show House event slated to kick off on Saturday.