Ashtray contents dumped in a trash basket caused a fire yesterday at a senior citizens high rise in Blawnox, the Allegheny County fire marshal's office reported this afternoon.

The four-alarm fire, reported around 9:30 a.m. by police from O'Hara and Blawnox who were directing traffic from the Route 28 detour, forced the evacuation of about 80 residents from the eight-story Blawnox Tower on Center Avenue.

Many of the residents were carried and otherwise assisted out of danger by the police who were first on the scene.

No injuries were reported.

The fire originated in a basket in a bedroom of a third-floor apartment. The tenant in that unit had left the apartment before the fire broke out.

Most of the approximately 80 residents found temporary housing last night with family and friends. Nearly two dozen were housed at the Landmark Manor on Route 8, Red Cross spokeswoman Theresa Creighan said yesterday.

Damage was estimated at $1 million or more, officials said.

Most of the residents would be allowed to return today to their apartments, the fire marshal's office said.