A fire that broke out in the University of Massachusetts Physical Plant led to heavy smoke and a closing of the building Friday afternoon.

Amherst Fire Chief Keith Hoyle said the University of Massachusetts Police Department contacted them around 2:46 pm and said that there was a potential fire on the first floor of the physical plant. Four engines and a ladder truck were called to the scene.

“It looked like the fire originated from a pile of cardboard boxes, but it’s still under investigation,” said Hoyle.

Amherst Engine No. 2 was the first on the scene. Upon entering the building, firefighters found heavy smoke and a fire. The fire began in the larger part of the plant, known as the bag house. Physical Plant Director Pat Daly said the bag house filters the soot that comes from the cold boilers, which resulted in the smoke that comes out through the smokestack.

“Normally, you can hardly see the exhaust that comes from the smokestack but right now you can see the heavy smoke,” said Hoyle.

The fire department closed off the building until 6:05 p.m. after they were certain the fire was completely out. A state fire marshal is currently investigating the scene to determine the exact cause of the fire, which is believed to be electrical.

Daly said that there’s a tendency for these types of fires, especially towards the end of the winter when the bag house has had a lot of activity due to the cold weather. The filters are working harder than they normally would because of the heating system. While the likelihood is high, Daly said these fires are not routine occurrences.

“It’s happened before. We had one about four or five years ago,” said Daly.

The fire didn’t affect heating or power on campus Friday afternoon, and was working up to its normal capacity. Daly said if it was the middle of the week things could have been worse.

“If we ran into very cold weather and it was the middle of the week things could have been a lot worse. Fortunately, it’s the weekend and the plant has less of a steam load,” said Daly.

This is at least the third fire of the semester. On Feb. 9, a fire starting with an electrical failure in a bathroom ceiling fan led to the destruction of two apartments in the North Village family housing section of campus. Another fire on the night of Feb. 12 started when a Van Meter resident tossed a cigarette butt into his trashcan.