A “Ghostbusters” cameraman helped police track down a woman who police said pushed a 72-year-old grandmother to the ground in Chinatown, leaving her with a fatal head injury.

The attack took place about 7:30 a.m. Wednesday at Essex and Chauncy streets, where a scene from the remake of the hit movie was being shot.

Tajanetta Downing, 24, of ?Jamaica Plain later told officers she was crossing the street when an elderly woman bumped into her, police said.

Downing, who stands 5 feet, 8 inches tall and weighs 190 pounds, told them she pushed the woman, who fell to the ground, and then she walked away but could hear a bystander asking the victim if she was OK, police said.

Yuzhen Lei hit her head on the pavement and was taken to Tufts Medical Center, where she was treated for a skull fracture, brain swelling and bleeding and was placed on life support, Assistant District Attorney Amy J. Galatis said.

Lei was pronounced dead last night.

The cameraman who saw the attack followed Downing long enough to get a description of her for police, Galatis said.

“Yeah, I was involved in an ?altercation with an older woman,” she told officers, according to a police report. “She pushed me, and I pushed her back, and I kept it going. I worked overnight and got off at 6 in the morning.”

The incident occurred across the street from where Melissa McCarthy, Kristen Wiig, Kate McKinnon and Leslie Jones have been filming “Ghostbusters” this week. The cast and crew have been set up at the corner of Harrison Avenue and Essex Street at the Kaze Shabu Shabu restaurant, which has been transformed into a New York eatery for the flick.

Downing was arrested on charges of aggravated assault and battery, and assault and battery on a person 60 or older.

Downing sobbed during her arraignment in Boston Municipal Court as Galatis told Judge Myong J. Joun the victim was not expected to live more than 24 hours.

“She is distraught right now, having heard what happened,” her court-appointed lawyer, Thomas P. Glynn, told Joun. “This was an accident. It was not an intentional act.”

Galatis recommended that Downing be held on $100,000 cash bail, citing two open assault cases against her in Dorchester District Court.

Joun revoked Downing’s bail for those cases and set new bail at $75,000 cash, pending an ?Aug. 5 pretrial hearing.

Standing at the same intersection where the attack occurred, the cameraman declined to comment yesterday.

“It was distressing at the time,” he told the Herald, “and I’d rather not talk about it.”

The movie has been in production here for about two weeks and will be shooting through September. It is scheduled for release in July 2016 and is expected to be one of the biggest films of that summer.

Gayle Fee contributed ?to this report.