CHELSEA, Manhattan (PIX11) — A 71-year-old man died six weeks after being attacked by a teenager on a Chelsea street in September, authorities said Wednesday.

The victim, Hbrad Boonshaft, and the 15-year-old boy got into an altercation in front of a pizzeria at 288 Eighth Ave. on Sept. 15 at around 4 p.m., police said. The teen then allegedly punched Boonshaft numerous times, according to the NYPD.

The victim was taken to the hospital with head trauma and died of his injuries on Sunday, police said.

It was unclear what prompted the fight. The suspect and victim did not know each other, police said.

The teen was taken into custody the day of the incident and was charged with assault, injured victim 65 or older, but the charge could be upgraded, officials said. The suspect has already been arrested a dozen times this year, according to a law enforcement source.