NEW YORK - Gunfire erupted in the storied Waldorf-Astoria hotel during a brazen robbery attempt Saturday at a lobby jewelry store, wounding a security guard and sending guests diving for cover.

The 54-year-old guard was shot in the chest but was expected to survive, and a suspect was in custody, police said. Charges were pending.

Hotel guest Christine Cataldo said she was looking at a display of engagement rings near the entrance to the store, Cellini Jewelers, when she heard the first shot.

“It sounded like a bomb. One big boom. And then people started running,” said Cataldo, of East Moriches on Long Island. “I looked up, and I saw a man in a suit with silver hair grabbing another guy.”

The mayhem began when the 20-year-old suspect, wearing a black track suit, pulled out a gun in the jewelry store and used the weapon to smash two display cases full of expensive rings and necklaces, said a police official who spoke on condition of anonymity because detectives were still investigating.

The security guard, a retired detective, confronted the man. About three gunshots rang out as the two wrestled and fell to the floor, though it wasn't clear who fired, the official said. Both were armed. One bullet hit the guard in the left upper chest, the official said.

Another hotel employee then tackled the suspect, the police official said.

The suspect's gun went off again as they grappled, but that bullet apparently struck no one. Hotel security staffers arrived and took the suspect into custody.

Witness Jeff Johnston of Raleigh, N.C., said he was near the store when chaos broke out.

“All of a sudden people were running and hiding behind hotel furniture,” he said.

The suspect was not identified. The wounded guard was taken to Bellevue Hospital, where he was in stable condition, police said.

The Waldorf-Astoria was the world's largest hotel when it opened on Park Avenue in 1931.