Jury selection began yesterday in the trial of an 18-year-old man charged with setting a house fire that killed six people in Youngstown, Ohio.

The suspect, Michael A. Davis, is accused of aggravated murder and aggravated arson in the Jan. 23 fire that took the lives of four small children, their mother and grandmother.

Because Mr. Davis could face the death penalty if convicted, prospective jurors are being questioned individually by prosecutors, defense lawyers and the judge. Once a jury is selected, his trial should last about a week.

Mr. Davis lived two blocks from the victims on Youngstown's East Side. Mahoning County prosecutors allege that he set their porch on fire, causing the 83-year-old house to quickly go up in flames. Fire investigators said the arsonist fed the fire with gasoline or something similar.

Killed were Carol Crawford, 46; her daughter, Jennifer R. Crawford, 23; and Jennifer's children, Ranaisha, 8; Jeannine, 5; Aleisha, 3; and Brandon, 2.

Five other people escaped from the house.

In court filings, prosecutors allege that rage motived Mr. Davis. They say he targeted the house because he believed someone who lived there stole his cell phone.

Carol Crawford worked two jobs to support her family, spending her days at a thrift store and evenings at a grocery. She walked to and from work, but never complained because she was devoted to her grandchildren, coworkers said.

Mahoning County Common Pleas Judge R. Scott Krichbaum has imposed a gag order barring prosecutors and defense lawyers from discussing the case outside the courtroom. He hopes the restraint will make it easier to pick a jury.