PHILADELPHIA » A mother and three young sons were struck and killed while trying to cross a busy Philadelphia highway after dark, and police today were questioning a driver who may have been drag racing.

A fourth son was injured in the crash Tuesday night on Roosevelt Boulevard, a major artery that divides neighborhoods in north and northeast Philadelphia. The highway has become notorious for pedestrian fatalities, many of them at night and several involving drag racing.

Samara Selena Banks, 28, was pushing a stroller while crossing the boulevard with her four sons at about 10:30 p.m. when they were hit by a 2012 Audi, police said. The car appeared to be racing a 1994 Honda, witnesses told police.

Banks and her 23-month-old son died at the scene. The three other children were taken to hospitals, where the 7-month-old and 4-year-old were later pronounced dead. The surviving 5-year-old was in stable condition with bumps and bruises, police said. They identified the 7-month-old as Saamir Williams but did not immediately release the other boys’ names.

No arrests had been made, but police said today that charges were pending.

Police Chief Inspector Scott Small said there is a crosswalk near the area where the family was trying to cross, but it wasn’t immediately clear whether they were using it. Investigators said they were looking for surveillance video at the accident scene as they tried to piece together what had happened.

"We’re talking to several persons who witnessed this accident — some who were on foot, some who were in other vehicles when the accident occurred," Small said. "We’re getting some information that there may have been drag racing."

Relatives told reporters that Banks was returning home after visiting an aunt.

The accident closed the southbound lanes of the highway for hours before they were reopened at about 6 a.m. today.

In the wake of previous pedestrian deaths, city officials have called for more crosswalks and speed patrols on the boulevard.

Last August, 43-year-old Michael Romano died after pushing his 5-year-old son out of danger just before he was struck by a hit-and-run driver at 11 p.m. The driver was arrested three blocks away by a police officer who witnessed the crash, and was charged with vehicular homicide.

His death came just days after another man was killed in a 2 a.m. hit and run on the same stretch of road, which in that area is a divided, 12-lane highway.

In June 2009, 36-year-old pedestrian Brenda Rodriguez was struck and killed after she and a friend picked up Chinese food. Witnesses said she was struck by one of two drivers racing against each other, both of whom fled.