Twenty-one University veterans remained homeless yesterday after a fire early Friday evening destroyed their house, injuring no one but killing a pet dog and cat.

About 54 Alpha and 12 Boalsburg firefighters struggled for an hour to control the rapidly-spreading fire that poured thick smoke though the three-story wood frame house, located at 227 E. Nittany Ave., as hundreds of spectators looked on in amazement.

One resident, University student Dennis Gustafson, jumped from his window onto a second-floor roof and then into the arms of a crowd watching below. Five other residents crawled out of the house to safety after they discovered the fire at about 4:40 p.m.

Fire officials said yesterday they are still investigating the cause of the blaze which they say started in a first floor game room at the rear of the house and have not ruled out arson. The house is owned by Howard L. Gregg of 127 W. Outer Drive.

Several phone calls from neighbors reporting the fire poured into the Centre County Communications Center, the first at 4:37 p.m. Fire trucks arrived at the scene at 4:44, Kauffman said.

The house was home to 21 active members of the Penn State Veterans Organization, most of them University students. They are being housed temporarily around the borough and on campus by friends.

Perched on ladder towers from aerial trucks, firefighters attacked the flames from above while others on the ground doused the structure from three sides -- East Nittany Avenue, a lot on the east side and an alley behind the house. The dousing created a massive cloud of brown smoke and steam that could be seen for miles.

Firefighters faced a tense moment when electric lines from the burning house collapsed and fell across a fire truck, but no one was hurt, Alpha Fire Chief Robert Kauffman said.

About a half hour into the fire, tow trucks pulled away four cars parked below the raging third floor facade. Minutes after the last car was removed, the roof collapsed, showering flames and debris into the vacant spaces.

Kauffman said the fire, which was fanned by 10 to 20 mph winds, spread quickly through the old wooden structure. "Whatever happened, it happened fast," he said.

The fire was under control by 5:45, he said.

Kauffman said firefighters started their attack on the flames from inside the house but were forced out when it became apparent that the structure was going to collapse.

Gustafson, wrapped in a blanket outside the house, said he was awakened by a smoke detector.

"It actually worked," he said of the alarm. "I woke up and the room was full of smoke, then went to the window and everybody was yelling 'jump! Jump!' "

Mike Dawson, the Veterans House manager, said he saw no signs of fire when he entered the house at 4:35. He walked to his third floor room and turned on the television set. Ten minutes later, smoke filled the hallway, he said.

"I couldn't see to get down the steps," he said. "I threw a coat over my head and got out.

"I came to check things out and 10 to 12 minutes later the place was in flames. That doesn't make sense," he said."

As he spoke outside the building, the rear third floor roof collapsed in a wall of flames and thick smoke forced spectators back from the house.

"There goes everything we have," he said.

A few spectators cheered at the spectacle. "Get your ice cold soda!" yelled one crowd member. "Man, I told you to bring the marshmallows," shouted another.

Firefighters remained at the scene until about midnight, soaking the structure to prevent rekindling, Kauffman said. The Alpha Fire Company of State College and the Boalsburg Fire Company brought four fire trucks with water pumps, two ladder trucks and one equipment truck. The two companies used a total of about 360,000 gallons of water from three fire hydrants, Kauffman said.

In 1970, a fire destroyed the house, which was a fraternity at the time. A group of returning Vietnam veterans decided to reconstruct the house and they moved in two years later. All residents were students or recent graduates of the University.