Residents of Catasauqua's Silver Manor Adult Living apartments were able to re-enter their homes Saturday, escorted by the building owner, to claim needed belongings. But, it will be some time before the living quarters in the rooming house at 2 Front St. are habitable.

A fire that Catasauqua Fire Chief Richard Hertzog said started on the exterior of the building eventually gutted a fourth-floor apartment and left the entire building with water damage.

Firefighters from Catasauqua, North Catasauqua, Whitehall, Han-Le-Co, Northampton, East Allen, Woodlawn, Greenawalds and Nancy Run fire companies responded to the call, which came in at about 3:45 p.m. last Thursday, May 2.

Also on the scene were Northampton Regional and Macungie EMS.

Catasauqua police were the first on the scene, and began evacuating residents from the building.

Someone had called 911, reporting smoke seen coming from the building, about the same time that the automatic fire alarm sounded in the building, Hertzog said.

Last year, the apartment facility had been the site of numerous false alarms sounding, but Hertzog said the alarm system was serviced and the problem had not occurred for several months.

He also said the building, owned by Fred Silver, had passed previous building inspections.

Hertzog said Catasauqua Fire Marshal Ray Anthony investigated the building and ruled the cause of the fire to be "accidental undetermined."

"We don't know what started it," Hertzog said. "The occupant was asleep at the time."

He said the fire appears to have started in the area of exterior wood trim around a window, which is very old and dried out, but it is not possible to determine what caused it to ignite.

The electric and water service to the apartment building has been disconnected and a portion of the roof above the gutted apartment is missing, he said.

A sprinkler system activated, causing water damage throughout the building, including in the basement.

Once evacuated, residents rallied in the parking lot as firefighters worked to extinguish the blaze.

No one was injured.

The American Red Cross Greater Lehigh Valley Chapter reported it assisted 23 individuals who were displaced by the fire. The Red Cross provided lodging and food for four people and said the owner of the building provided alternative housing for those needing it.

Hertzog said firefighters were on the scene until about 8:30 p.m.