Air France has told families of passengers on Flight 447 that the jetliner broke apart and they must abandon hope that anyone survived, a grief counselor said Thursday as military aircraft tried to narrow their search for the remains of the plane.

Air France CEO Pierre-Henri Gourgeon told the families in a private meeting that the plane broke apart either in the air or when it slammed into the ocean, according to Guillaume Denoix de Saint-Marc, who was asked by Paris prosecutors to help counsel family members and was at the Wednesday meeting. The plane, carrying 228 people, disappeared after leaving Rio de Janeiro for Paris on Sunday night.

Investigators were relying heavily on the plane's automated messages to help reconstruct what happened to the jet as it flew through towering thunderstorms. They detail a series of failures that end with its systems shutting down, suggesting the plane broke apart in the sky, according to an aviation industry official with knowledge of the investigation. He spoke on condition of anonymity because he was not authorized to discuss the crash.

"What is clear is that there was no landing. There's no chance the escape slides came out," said Denoix de Saint-Marc, who heads a victims' association for UTA flight 772, shot down in 1989 by Libyan terrorists.

Gourgeon told families there were no survivors, according to Denoix de Saint-Marc. That makes this Air France's deadliest plane crash and the world's worst commercial air accident since 2001.

Military rescue planes were trying to narrow the search zone Thursday as ships headed to the site to recover wreckage. Brazilian military planes located new debris from Air France Flight 447 Wednesday, after spotting an airline seat and oil slick a day earlier.