A 3-year-old girl was struck by a pickup truck and killed yesterday when she darted into a Lawrenceville street toward a relative who had just arrived in a car to take her home.

The girl was at a babysitter's house in the 4700 block of Hatfield Street, a strip of row houses where children play on porches and sidewalks during warm summer days. Some of them were outside about 6:10 p.m., when, police said, the girl ran out from between parked cars and was struck by the Ford F-250 truck.

Police said she was probably too short to see it coming.

The driver, whose name was not released, immediately stopped and cooperated while accident investigators and homicide detectives scanned the scene and talked to witnesses.

The girl was taken to Children's Hospital, where she was pronounced dead. The medical examiner's office did not disclose her name last night.

Early investigations suggest her death was a tragic accident, police said. The details of the incident were still under investigation, Cmdr. RaShall Brackney said.

"There seems to be a lot of kids and adults in the area who saw what happened and quickly called 911," Cmdr. Brackney said. "We'll be thoroughly investigating the incident to make sure there is no culpability."

No charges were filed last night.

"I heard screams, and then I looked out my bedroom window and there was a small child on the street," said Kate Bayer, 59, who lives on the block, where small children play at all hours, she added, sometimes unsupervised. "They're in the street, there's a disregard for traffic. We've been fearful that what happened here tonight was going to happen."

The girl -- nicknamed "Nee Nee" -- lived on the block until a few weeks ago, when she moved to live with an aunt, neighbors said. She loved to play with SuzAnne Thorp's young grandchildren, sometimes outside in their backyard pool.

"She was just a cute little girl," Ms. Thorp said.

Children flood the block when the weather is warm, neighbors said, riding up and down the street on their bikes, sometimes at night. Hatfield Street "natives know it's a minefield, we all go five miles per hour," but strangers to the block might not be aware, said Kate Bagin, 42, a resident of the block.

She and other neighbors said the girl's death underscores the need for more signs on the street, which they said has become a busy thoroughfare through Lawrenceville. A playground, they said, would offer children a safer place to spend their summer days.

"I'm heartbroken," Ms. Bagin said. "I'm heartbroken for the driver, I am heartbroken for the child, and I'm heartbroken for people on the street who have had to see this happen."