NEW YORK (AP) - A doctor forced from a New York hospital because of sexual harassment accusations returned Friday with an assault rifle hidden under a lab coat and shot seven people, killing one woman in an attack that left several doctors fighting for their lives, authorities said.

The gunman, Dr. Henry Bello, fatally shot himself after trying to set himself on fire at Bronx Lebanon Hospital, they said. He staggered, bleeding, into a hallway where he collapsed and died with the rifle at his side, officials said.

Witnesses described a chaotic scene as gunfire erupted spreading terror throughout the medical facility as employees locked themselves inside rooms and patients feared for their lives.

"I thought I was going to die," said Renaldo Del Villar, a patient who was in the third-floor emergency room getting treatment for a lower back injury.

Law enforcement officials identified the shooter as the 45-year-old Bello, who was described on the hospital website as a family medicine physician. Officials said Bello used an AR-15 assault rifle in the attack on the 16th and 17th floors.

Bello was allowed to resign from the hospital in 2015 amid sexual harassment allegations, according to two law enforcement officials. The officials didn't know the details of the allegations.

The officials were not authorized to discuss the still-unfolding investigation and spoke on condition of anonymity.

In unrelated cases, the doctor had been arrested in 2004 on a charge of sexual abuse, according to a police report, after a 23-year-old woman told police Bello grabbed her, lifted her up and carried her off, saying, "You're coming with me." He was arrested again in 2009 on a charge of unlawful surveillance, after two different women reported he was trying to look up their skirts with a mirror.

Ultimately, one female doctor was killed and six others wounded - five seriously, according to Police Commissioner James O'Neill. The patients were treated in the emergency room at Bronx Lebanon.

"This was a horrible situation unfolding in a place that people associated with care and comfort, a situation that came out of nowhere," Mayor Bill de Blasio said, adding that terrorism was not involved in the attack.

Shortly after receiving a 911 call about an active shooter, police officers went floor by floor, their guns drawn, looking for the gunman. They later learned he was dead inside the building. De Blasio confirmed that the Bello killed himself.

Bello may have doused himself with an accelerant like gasoline and tried to set himself on fire before shooting himself, officials said. Sprinklers extinguished the fire.

According to New York State Education Department records, Bello had a limited permit to practice as an international medical graduate to gain experience in order to be licensed. The permit was issued on July 1, 2014, and expired last year on the same day.

Employees and their loved ones described the horrifying moments as they scrambled for information.

Garry Trimble said his fiancee, hospital employee Denise Brown, called him from inside the hospital to tell him about the gunman.

"She woke me up and told me there was a situation, somebody's out there shooting people," Trimble said as he waited for Brown to leave the hospital. "I could hear in her voice she was shaking and about to cry."

Gonzalo Carazo described the scary scene to WCBS-TV. "I saw one of the doctors and he had a gunshot wound to his hand," Carazo said.

"All I heard was a doctor saying, "Help, help!" Carazo locked himself in a room for about 15 minutes until police came and led him out of the hospital.

The 120-year-old hospital has nearly 1,000 beds and one of the busiest emergency rooms in New York City. It is about a mile and a half north of Yankee Stadium.

In 2011, two people were shot at Bronx Lebanon in what police said was a gang-related attack.

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