A 27-year-old mother of four was killed early yesterday when fire engulfed all three floors of a Northwest Washington home, but nine family members were able to escape, including an infant who apparently was thrown from a second-floor window into the bed of a pickup truck. Four persons were injured.

John Henry Dantzler, who D.C. fire officials said was about two blocks from the house at 430 Upshur St. NW when he heard screaming and saw smoke pouring from the house, discovered the infant in the truck after coaxing a woman to jump from a rear second-floor window.

The dead woman, whose body was found in a second-floor bedroom, was identified by her father, Otis Byrd, 46, as Joanne Elizabeth Byrd. He said she had moved into the house with her children about two months ago and was looking for an apartment for her family.

Bryd said the house in which his family had lived for 16 years was equipped with smoke detectors, but it was unclear yesterday if they had sounded.

Byrd said that when he left the house about 6 a.m. to go to his job in Beltsville there were "no problems." When he arrived in Beltsville, co-workers told him his house had caught fire.

Byrd's wife Ellen, 46; a grandson, Walter Byrd, 14 months, and two of their sons, Kevin, 19, and Fredrick, 15, suffered burns and were cut when they fled the blazing house through upper-floor windows.

Walter was in fair condition yesterday at Children's Hospital with burns on his hands and suffering from smoke inhalation, according to a hospital spokeswoman.

Ellen Byrd, who suffered minor burns and a neck fracture, and Kevin, who suffered minor cuts and burns on his arms, were both in fair condition at the Washington Hospital Center, a spokeswoman said. She said Fredrick was treated for cuts and burns on his arms and released.

Larry Nellums, Joanne Byrd's estranged husband, said their four children escaped from the house unharmed. Otis Byrd said that his two sons fled from a second-floor window above the front porch.

Fire department spokesman Ray Alfred said it took about 85 firefighters about 30 minutes to control the two-alarm blaze, which was discovered about 6 a.m. He said that the cause of the fire, which was apparently accidental, is under investigation. Damage was estimated at $100,000.

Inez Redwood, whose house at 432 Upshur St. NW shares a wall with the Byrd residence and received about $10,000 damage, said she was awakened by someone banging at her front door. When she went downstairs, Redwood said, "all I could see was fire coming out of the house next door. It was belching out. A neighbor was standing on the street yelling, 'Get out of your house!' so I went upstairs and got my sister. When we got out, I could hear someone in the back yelling, 'Jump! Jump!' "

Byrd, who said home improvement is one of his hobbies, said that the house had been rewired recently.

"I did some of the ceiling work . . . . The wood and paneling I handle, but not the wiring," he said.

Byrd said the family hopes to stay with relatives over the holidays while the home is rebuilt. "It's my house," he said. "I can't afford to buy another."