Fire and law-enforcement authorities have determined a house fire Wednesday afternoon in Gladwyne was intentionally set, Lower Merion Chief Fire Officer Chas McGarvey said.

A fire was reported on the third floor in the rear of 1401 Spring Mill Road about 3:30 p.m. Wednesday, to which the Gladwyne and Bryn Mawr companies responded, with Narberth and Ardmore companies, and Narberth Ambulance, assisting.

According to McGarvey, electricians working in the house heard a smoke alarm, found a window on fire in a third-floor bedroom and threw water on it. Smoke damage resulted, and walls had to be opened. No injuries were reported.

Investigators determined that someone intentionally set the fire; township police and county and state investigators were called to the scene. McGarvey said there is a suspect identified in the case, which is now under the jurisdiction of the Montgomery County District Attorney's office.