by Alison Gendar
Daily News Staff Writer
Monday, June 1st 2009, 4:00 AM

A Bronx infant has become the fifth New Yorker suffering from swine flu to die, the boy’s family and an official close to his case told the Daily News yesterday.

Eleven-week-old Steven Montañez was already sick with swine flu when his aunt found the boy unconscious on Thursday, an autopsy revealed.

“I went in to check up on him, I turned him around and he was purple,” said his aunt, Jennifer Castellanos, 18. “He was a completely healthy baby.”

“The Health Department told us he died because of swine flu,” she added.

The boy’s father was inconsolable with grief.

“I have nothing to live for anymore,” said the father, Louis Montañez. “You don’t know how painful this is. We’re going through such a bad situation right now.”

A source familiar with the infant’s case confirmed he was sick with swine flu, but the medical examiner had not yet determined if the H1N1 virus caused his death.

Jessica Scaperotti, spokeswoman for the city’s Department of Health and Mental Hygiene, would not confirm or deny the cause of death.

The city has refused to release information about three of the other victims.