An 11-year-old boy was found yesterday fatally stabbed in a Southeast apartment, after the boy's mother -- who was also stabbed -- spent a harrowing 13 hours Tuesday night and Wednesday morning being driven around town by the assailant, police and hospital officials said.

Christopher Powell, of 2905 Fairlawn Ave. SE, was found by D.C. police and firefighters around 2 p.m. yesterday, confirming a horror that the boy's mother had been coping with for half a day, officials said.

Dorothy Powell, 34, was listed in fair condition last night at Holy Cross Hospital in Silver Spring, where she had undergone surgery for two knife wounds in her upper back and one wound in her neck. The wounds had so weakened her that she was initially unable to communicate to officials that her son might be hurt as well, said John Walker, a hospital spokesman.

Last night, police arrested Willie Baskerville, 30, of 14721 Blanton Rd., Silver Spring, in connection with the incident. Baskerville, who friends and officials said was Powell's estranged boyfriend, was being interviewed by homicide detectives after midnight and criminal charges were being prepared, said Capt. William White III, a police spokesman.

The incident, according to police and hospital officials, apparently began as a domestic argument in the Powell apartment between 10 and 11 p.m. Tuesday, shortly after Powell had returned from work. White said police were not alerted to the argument Tuesday night.

During Tuesday's argument, both Powell and her son were apparently stabbed, police said. Powell, apparently unaware that her son had been wounded, later told hospital officials that she believed the boy had been locked in a closet.

After the stabbing, the assailant apparently put her in a car, saying he would take her to the hospital, hospital officials said. For the next 13 hours, the two would drive around town as Powell slowly bled, authorities said.

Police and hospital officials said that Powell was taken to Baskerville's Blanton Street home in Silver Spring sometime late yesterday morning. Then a woman at the house took the wounded woman to Holy Cross Hospital.

Walker, director of communications for Holy Cross, said Powell was admitted to the emergency room around 12:30 p.m. yesterday.

For an hour, Walker said, Powell struggled to speak as surgeons treated her for collapsed lungs. However, a surgeon had to insert a chest tube to reinflate the collapsing lung, thereby preventing Powell from talking further.

When she had recovered enough to talk, Walker said, she immediately told hospital personnel that her son might be hurt. Officials, who had notified police of the stabbing victim, called them back to alert them to the possibility of a second victim.

Police went to the Southeast apartment just before 2 p.m. yesterday. They found the front door locked, but noticed a window on the second floor was open, police officials said, and called the D.C. Fire Department to help. When they finally entered the apartment a few minutes later, they found the boy dead in a bedroom. He had been stabbed several times, White said.

Neighbors in the Twining community, which abuts the Anacostia Freeway, expressed shock over the death of Christopher Powell, a sixth grader at Kimball Elementary School whom they described as a friendly and active boy.

"I've never known anything like this to happen and I've lived here 20 years," said neighbor Geraldine Ferguson. "It's sad."

"He was a nice little boy. He used to play with my grandchildren all the time," said another neighbor, Elsie Deadwyler. "It's a gorgeous neighborhood. That's why it's so sad."

James Brady, Dorothy Powell's brother, said his sister had been trying to stay away from her former boyfriend and that a court order requiring him to stay away from her was issued after he was charged with stabbing her on July 15.

In that incident, neighbors said, Powell was cut on the side of the head and collapsed in the street outside her apartment as her son tried to lead her to safety.

Police arrested Baskerville last night around 8, White said, at 748 Congress St. SE. Baskerville is expected to be arraigned today.