An infant boy delivered prematurely after his traffic agent mother was struck by a van and pinned under a bus has died, authorities said Friday.

Sean Michael Justin Sanz had been in intensive care since he was delivered by Caesarean section shortly after a runaway van hit his mother on Aug. 14. He weighed 3 pounds, 6 ounces at birth.

His mother, traffic agent Donnette Sanz, survived the delivery but died about an hour later in an emergency operating room. She was seven months pregnant.

The van, driven by a 72-year-old man with what authorities say is a long history of driving offenses, hit Sanz when she was crossing a Bronx street on her lunch break. The impact sent her flying into the path of a yellow school bus, which ran her over. About 30 bystanders helped hoist the 5-ton bus from her body in a rescue that made the front pages of the city's tabloid newspapers.

"He meant everything to me," Rafael Sanz said of his tiny son. "He died in my arms."

Sanz had harsh words for the van's driver, Walter Walker: "I hope he really does rot in hell. I hope he dies a horrible death."

In an interview with the Daily News published hours before the infant's death, Rafael Sanz spoke about how his deep love for his son was mingled with grief over his wife's death. He said she had donated a kidney to him shortly before their wedding four years ago.

"She never got to see our baby, but she was in love with him," he said.

Donnette Sanz had been a civilian member of the NYPD for two years. Traffic agents direct vehicles, write parking tickets and operate tow trucks. They do not carry weapons.

Walker has not entered a plea to charges of criminally negligent homicide and aggravated unlicensed operation of a motor vehicle, said his lawyer, Michael Torres.

He said Walker was "devastated" by what happened. Torres said he didn't know if Walker was aware of the child's death.

A spokesman for the Bronx district attorney said Friday that prosecutors would wait for the medical examiner to determine the infant's cause of death before deciding whether Walker would face additional charges.

Walker has a history of driving offenses and arrests dating to the 1980s; police have said he had his license suspended 20 times. In a court filing, police said the brakes on Walker's van had deteriorated so badly it was unsafe to drive. Walker has said he tried to avoid hitting Sanz but was unable to stop.