MONTERREY, Mexico (AP) — U.S. authorities confirmed Monday that Jenni Rivera, a U.S.-born singer whose soulful voice and openness about her personal troubles made her a Mexican-American superstar, was killed in a plane crash in northern Mexico.

The National Transportation Safety Board said it was sending a team to help investigate the crash, and the board said Mexican authorities had informed them that Rivera had died in the accident.

Rivera's relatives in the U.S. already had few doubts that she was on the Learjet 25 that disintegrated on impact Sunday in rugged territory in Nuevo Leon state in northern Mexico.