A fire that destroyed four rowhouses and damaged 10 others in West Philadelphia was the work of an arsonist, Fire Commissioner Lloyd Ayers said yesterday.

The three-alarm blaze started about 11:25 p.m. Saturday when clothing and other belongings were set afire on a porch at 5815 Cedar Ave., Fire Department investigators determined.

Neighbors said the items belonged to tenants who recently were evicted from that address.

Southwest Detectives were investigating and no arrests were reported yesterday.

Two women and a man were taken to hospitals for treatment after the fire, but none of their injuries was life-threatening, officials said.

It took firefighters more than 80 minutes to control the blaze.

Ayers also reported that a fire that killed a woman in West Philadelphia earlier Saturday was caused by an unattended iron.

The Medical Examiner's Office said Delorise Riley, 65, died of smoke inhalation suffered in the fire at 17 S. Redfield St.

Firefighters found two working smoke detectors and one with a dead battery in the house, Ayers said.

Contact staff writer Joseph Gambardello at 215-854-2153 or jgambardello@phillynews.com.