RIO DE JANEIRO, Brazil - Investigators and independent analysts trying to determine why Air France Flight 447 broke apart in a violent storm over the Atlantic stressed they don't know why a plane that seemed to be flying normally crashed just minutes after the pilot messaged that he was entering an area of extremely dangerous storms.

Air France Chief Executive Officer Pierre-Henri Gourgeon told family members at a private meeting that the plane disintegrated and that there were no survivors, according to a grief counselor who was asked by Paris prosecutors to aid relatives.

More than 500 people packed the historic Candelaria church in the center of Rio de Janeiro yesterday for the victims' Mass.

With the crucial flight recorders still missing, investigators were relying on the plane's automated messages to help reconstruct what happened. as the jet flew through thunderstorms.

However, they will have little to go on until they recover the plane's "black box" flight data and voice recorders, now likely on the ocean floor miles beneath the surface.

France's defense minister and the Pentagon have said there were no signs of terrorism .

Other hypotheses haven't been ruled out. *