City fire investigators believe that a five-alarm fire that destroyed several townhouses on Marchand Street in Shadyside was the result of a cigarette that was tossed into a trash can.

Twenty people were displaced by the fire that started in a second-floor bathroom at 6338 Marchand, a privately owned condominium, said officials at the city Fire Bureau. The fire traveled between the walls and up to the roofs of several adjacent units, which are operated as apartments.

No one was injured in the blaze, which was determined to be accidental.

Yesterday, workers secured broken third-floor windows with plywood and put tarps over large holes in the roofs. All of the buildings will be repaired, said Jeffrey Sippel of McQuarters Realty, which manages the apartments.

Sunday's five-alarm fire began just before 7 p.m. and was under control by 9:15 p.m. Firefighters were still working at the scene until nearly 5 a.m. yesterday morning, 911 dispatchers said.

Ben Byron, a Pitt graduate student, said he noticed a smoky haze coming into his apartment from the adjoining building. He called 911.

Joshua Han, a business student at Carnegie Mellon, said smoke and water destroyed his television, laptop computer and other electronic devices.

"In the grand scheme of things it's just stuff," Mr. Han said. "I'm just glad no one was hurt."

Among the townhouses that were badly damaged was one that was once the home of writer and author Willa Cather, who lived in Pittsburgh from 1896 to 1906.

The three-story brick condominium townhouse at 6338 Marchand St., was the home of Miss Cather's employer, James W. Axtell, who hired her as managing editor of his new magazine, The Home Monthly.

Between at least 1890 and 1939, the seven adjacent townhouses on Marchand Street were owned by John R. Rush, partner with Mr. Axtell in the East Liberty printing and stationery business Axtell, Rush and Co., publisher of National Stockman and Farmer.

Mr. Axtell also was a partner in Axtell, Orr and Co., which published the first issue of The Home Monthly in August 1896.

Much of what is known about Miss Cather's early days in Pittsburgh comes from letters to Mr. Gere's wife and daughters, in which she expresses surprise that the only ornament in the parlor of the Axtell home was a crayon portrait of James' father Phillip, a Presbyterian minister who established the Cumberland Presbyterian Church at Shady Avenue and Aurelia Street. She found the Axtells friendly but reserved.

After Miss Cather left the magazine in June 1897, she worked as a writer and drama critic for the Pittsburgh Leader and the Pittsburgh Gazette, and taught at two city high schools: Central in the Hill District and Allegheny on the North Side.