A 19-year-old drug suspect fleeing police struck and killed two children in a crosswalk at noon yesterday as he barreled through a red light in Northeast Washington, police and witnesses said.

Police said officers had broken off their pursuit of the man several blocks from the crosswalk, at Florida Avenue and 12th Street, but one resident who said she witnessed the collision vigorously disputed that assertion.

Authorities have opened an investigation into whether the officers observed the D.C. police department's pursuit policy, and officials cautioned late yesterday afternoon that they considered their account preliminary.

The children -- Christopher Suydan Jr., 7, and his sister, Octavia Suydan, 8, both of Temple Hills -- were on an outing with their father, Christopher Suydan Sr.

They had stopped to have a tire repaired and were crossing Florida Avenue to get something to drink. The children were several steps ahead of their father when they were struck, police and his relatives said.

The driver, Eric Palmer of the 1200 block of 19th Street in Northeast, was charged with two counts of second-degree murder, and police said he may face additional charges. Yesterday was Palmer's 19th birthday, his grandmother said.

The children, whose parents are separated, lived with their mother, Towhanna Boston. She said she learned of the tragedy when her husband left a message asking her to call him. When she did, he told her to meet him at the hospital, where he was waiting with a doctor and social worker.

"It's hard to handle," she said. "Somehow we'll get through it."

A D.C. police spokesman, Sgt. Joe Gentile, said police were running a "buy-and-bust" narcotics operation at Sixth Street and Orleans Place NE, seven blocks from the intersection where the children were killed. Gentile said one man, later identified as Palmer, recognized the officers and "just took off and fled at a high rate of speed."

Police "did initiate a pursuit -- this is my understanding -- but [it] was quickly broken off by orders several blocks from here," Gentile said, standing near the yellow police tape that cordoned off the intersection.

He said Palmer continued to flee "at a high rate of speed," weaving into the oncoming lane and through the red light, striking first the children and then a car driven by a 17-year-old from Virginia. She was not seriously injured. As police cruisers converged on the intersection, Palmer fled on foot. He was apprehended a short distance away.

"It was not what would be considered an official pursuit because the pursuit was broken off several blocks from here," Gentile said.

But a 20-year-old who said she was on her front porch several doors down from the intersection when the collision occurred disputed Gentile's account.

"They didn't stop chasing that car," said Tiffany Rorls, 20.

The closest police car, she said, appeared to be about 10 feet behind Palmer's Accord. She said the vehicles appeared to be traveling at "like 90 to 100 miles an hour."

The marked police car had its lights and sirens on, she said. "It was like one [car] right on his tail, and then one or two more a ways behind them," Rorls said.

The District's pursuit policy -- one of the strictest such policies in the country -- says police can chase only suspects who pose an immediate physical threat to others. Assistant Police Chief Peter Newsham, who formerly headed the office of professional responsibility, said police would have violated the policy yesterday if they had chased someone suspected of trafficking in drugs who did not pose an immediate danger of injuring or killing someone.

"It may be a violation of police department policy," he said. "Whether or not they were involved in a pursuit is something our office of professional responsibility will investigate."

Even if police had violated the policy, Newsham said, the officers would not be responsible for the children's death. "The blame lies solely on the shoulders of the driver who was fleeing," he said.

Some residents, however, said some of the blame rests with the police, who they insisted continued their pursuit.

"If you see that they're not going to stop and you're going through a residential area, what do you think is going to happen?" asked Tony Britt, who said he, too, was nearby. "There's going to be a crash. I'd say the police are more at fault than [the driver] is."

Christopher Suydan Jr., known as CJ, took karate classes with his father. His older sister Octavia, who went by Tavi, loved to sing and dance and imitate her brother.

Their mother said that they were inquisitive children and that they did well in school. She said both were on the honor roll.

"They were wonderful kids," Boston said.

Christopher was in the Talented and Gifted program at Longfield Elementary School in Forestville, where he was a third-grader, she said. Octavia was in the fourth grade at Hillcrest Heights Elementary School in Temple Hills.

Boston said her children were extremely close. Only a year apart, they both had birthdays next month -- Octavia on Oct. 1 and Christopher on Oct. 22. They had told their mother they each wanted a portable CD player. She said she had bought them watches but had not had time to make further plans for their birthdays.

"They would keep an eye on each other," Boston said. "If it had been the other way, and one of them got hurt and the other didn't, the other would have had a really hard time with it."

In a statement issued last night, Mayor Anthony A. Williams (D) said: "Our hearts go out to the Suydan family during this time of what must be unbearable sorrow. As a parent, I can only imagine the pain of losing a child. The city of Washington grieves with the family as they mourn this intolerable loss, and we will conduct a complete and thorough investigation."

At Christopher Suydan Sr.'s home in Laurel, recent photographs of the children sat atop a piano in an immaculate living room.

"They were just golden," said Tia Simmons, Christopher Suydan Sr.'s cousin.

She paused, doubled over and cried.

"My cousin had to watch his kids die, my cousin had to watch his kids die," Simmons sobbed. "That could have been me with my two" children.

She did not, however, blame police.

"They were trying to do their job," she said. "The guy who hit my cousins, he is to blame. He had no regard for life."

Palmer, the driver, lived with his grandmother Verna Palmer, 66, in a modest second-floor apartment. After learning of the day's events from a reporter, she said the news hit her "like a ton of bricks."

"I've had him all my life," Verna Palmer said, declining to say anything more.

Staff writers Lila Arzua, Carol Morello, Amit R. Paley and Clarence Williams and staff researchers Madonna Lebling and Meg Smith contributed to this report.

Christopher, left, and Octavia Suydan were walking near their father when struck by a car.After two children were struck in the crosswalk at the intersection of Florida Avenue and 12th Street NE, the driver struck the dark-colored car, center, although police said its driver was not seriously hurt. The suspect ran from his car, left, and was captured a short distance away, police said.