Two children in a stroller were critically injured late yesterday morning when they were hit by a pickup truck from the D.C. Water and Sewer Authority in Northwest Washington, authorities said.

The driver left the scene but was taken into custody a short time later after he was pointed out by witnesses, authorities said. Police said the driver, Thomas Davis, 47, of Northwest Washington, was charged with leaving the scene of a collision.

The children -- a 23-month-old boy and a 9-month-old boy -- were being pushed by their mother in a crosswalk at Georgia and New Hampshire avenues about 11:45 a.m. when they were hit by the truck, which was heading north on Georgia. Police said Davis apparently had run a red light.

The children, who live near the intersection, were in critical condition last night at Children's Hospital. The older boy, Jossan Zavala, has a skull fracture and broken leg, and the baby, Miguel Zavala, has two broken legs, authorities said. Their mother, Dilcia Zavala, 21, was not injured.

The children were thrown from their stroller and landed along with it on the sidewalk.

"This is just tragic. Two kids, just going home, and now they're fighting for their lives," said D.C. Council member Adrian M. Fenty (D-Ward 4).

Police said that two other motorists followed the truck after the accident and boxed it in on Sherman Circle, about eight blocks from the crash site. But Alan Etter, a spokesman for the D.C. Fire and Emergency Medical Services Department, said that an ambulance was passing through the circle when its crew was flagged down by passersby and directed to Davis.

The driver was sitting, head in his hands, on the front stoop of a house, Etter said, and told the ambulance crew he had been in an accident.

Authorities said that Davis has diabetes and that they were investigating whether the condition contributed to the accident. Davis has worked for the sewer authority for 20 years and was checking meters in the area yesterday, sewer authority officials said.

People near the busy intersection ran to help the family.

William Westray and Pete Stephenson, who were remodeling a storefront across the street, said they heard a loud thump and then screams.

"I heard the mother screaming, right off the bat," Stephenson said.

Westray and Stephenson said they and about 10 other people ran to the mother's side and saw the older child bleeding from a gash across his head. Passersby hailed a passing firetruck, they said, and the firefighters summoned more help.

"It took us a little while to get back to work," Westray said. "Because, I mean, I'm a father. That stuff hits home."

Staff researcher Bobbye Pratt contributed to this report.

Officer Robert Anderson inspects the stroller that was struck at Georgia and New Hampshire avenues in Northwest Washington.The shoes of the victims are left at the scene of the accident. The boys were thrown from their stroller; their mother was not injured.