LINCOLN, Neb. (AP) _ Investigators are looking into whether a fire at a fraternity house that killed a Nebraska Wesleyan University student was caused by a faulty laptop computer, an official said Monday.

``We're trying to eliminate it as a cause, or confirm it,'' said Lancaster County Attorney Gary Lacey.

Some laptop batteries have been recalled recently because they can catch fire. Lacey did not know what brand the laptop was.

A laptop found in the room of the student who died at the Phi Kappa Tau fraternity house has been sent for analysis to the U.S. Bureau of Alcohol, Tobacco, Firearms and Explosives.

It does not appear the blaze was set intentionally, said state Fire Marshal Dennis Hohbein. An arson-detection dog sent into the building did not detect any flammable liquids.

School spokeswoman Sara Olson has said some neighbors heard fireworks the night of the fire, but Lacey would not comment on whether fireworks may have sparked the blaze.

Killed was Ryan Stewart, 19; an autopsy revealed the cause was smoke and soot inhalation.

Three other students remained in the hospital Monday. David Spittler, 20, was upgraded to serious condition; and Travis Mann, 22, and Aaron McGuire, 20, were upgraded to fair.

The fire broke out around 4 a.m. Friday in a second-story room.

Nebraska Wesleyan, a Methodist Church-affiliated liberal arts college, has about 1,800 students.