Muggers killed a Provo man Sunday after he intervened when the assailants punched his mother and robbed his father in a subway station.

Brian Watkins, 22, of Provo, Utah, was in New York with his family for the U.S. Open tennis tournament on Sunday when he was attacked on a midtown subway platform, Transit Police spokesman Sgt. Bob Valentino said.Watkins, along with his father, mother, 26-year-old brother and his wife, ventured into the subway station at 53rd Street and Seventh Avenue for a two-stop ride to a station near the Tavern on the Green restaurant in Central Park.

As they waited on the northbound platform, five young men approached, a knife was brandished and the victim's father was robbed, Valentino said.

"During the robbery, one of the assailants punched the mother in the face and the two sons interceded," Valentino said. The victim was stabbed during the fight.

The robbers fled, Valentino said. Two men were questioned early today, but no immediate arrests were made.

Watkins was the 18th homicide victim in the New York subway system this year, Valentino said.