MUHLENBERG TWP., Pa. – The Pennsylvania State Police fire marshal says a massive fire that forced dozens of people from an apartment complex in Muhlenberg Township has been ruled an accident.

The rubble remains where parts of the Oak Forest Apartments once stood, and now, more than a month after a massive fire, investigators say an electrical malfunction sparked it.

“We’ve come to the conclusion that this is an accidental fire,” said Corey Heimbach, the Pennsylvania State Police fire marshal for Troop L.

Investigators spent weeks examining the scene, reviewing photos and videos, and conducting interviews.

“Canvassing through all the debris, looking at fire patterns, looking at mechanical components such as the electricity, the HVAC — all that stuff,” Heimbach said.

Authorities say apartment G-9 is where the where the fire was discovered, and they say the fire started in the space above the ceiling of the second-floor apartment.

“And the only competent ignition source within that area is electrical components,” Heimbach said.

The apartment was built in the 1960s, before many of today’s fire standards were in place.

“Obviously, fire codes, building codes, standards, you know, technology — all that stuff has changed over time,” Heimbach said.

So, was the building up to code?

“They meet all the codes for the codes that they were constructed under,” Heimbach said. “However, if a major renovation was to occur, they would have to then bring those buildings up to present code.”

People affected by the fire who need help can apply for special, low interest loans through the Small Business Administration.