BLACKSBURG -- Police are investigating a suspicious fire that gutted part of the Zeta Psi fraternity house on East Roanoke Street early Monday.

The blaze began about 1:45 a.m. when a couch on the porch caught fire, said Blacksburg Fire Chief Keith Bolte. The fire, which quickly spread to the inside of the house, was put out soon after firefighters arrived.

The fire burned out the first floor of the house, destroyed the porch, and caused heat and smoke damage on the second floor, Bolte said. The preliminary damage estimate is $75,000.

On Monday afternoon, Zeta Psi fraternity brothers gathered on the sidewalk in front of the charred house. Eric Kazlauskas, 20, from Canada, said five people lived in the house. All of them, along with a visitor, escaped without injuries.

The fraternity is working with Virginia Tech to find housing for the displaced students, he said.

The 2½-story house, once owned by Paul Derring (after whom Tech's Derring Hall is named), is in Blacksburg's Historic District.

The fraternity brothers wouldn't talk about how the fire began, but Kazlauskas echoed rumors that it had been set. "If someone gets arrested, we'll make a comment," Kazlauskas said.

Agents from the Bureau of Alcohol, Tobacco, Firearms and Explosives arrived Monday afternoon and began inspecting the house. Blacksburg police spokesman Bruce Bradbery said it is common for the ATF to help investigate fires and does not signify that police suspect foul play.

Still, rumors circulated through the campus community about how the fire began.

Pris Sears, who lives down the street from the fraternity house, said that as firefighters worked, she jokingly asked a police officer if he thought the couch fire had been set by West Virginia football fans. The officer told her no, he thought it was set by another fraternity, she said.

The Zeta Psi house has been targeted in the past. In May 2004, police found wood piled against the house that someone had attempted to light. A man was convicted of trespassing in the incident. A second Roanoke Street fraternity house -- Kappa Alpha -- was destroyed in 1997 by a fire set by a former Tech student.

But members of other fraternities on Roanoke Street said they doubted that anyone would try to damage the Zeta Psi house.

"Everybody on this street gets along," said Adam Neighbors, a 19-year-old Kappa Alpha member from Covington.

Out front of the Zeta Psi house, blackened trophies and a charred man-sized paddle sat on an electrical box in the yard.

Kazlauskas said the paddle dates to 1974, when the fraternity was chartered at Virginia Tech.