This gets more mysterious - AFF 447.

PARIS, France (CNN) -- The Air France plane that crashed last month with 228 people aboard "did not break up or become destroyed in flight," the French air investigation agency announced Thursday.


Brazilian Navy officers hold a wreath during a tribute held on Monday to victims of Air France Flight 447.
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"The plane went straight down ... towards the surface of the water, very very fast," air accident investigator Alain Bouillard said.

Based on visual study of the physical remains of the Airbus A330 that have been recovered, "we were able to see that the plane hit the surface of the water flat. Therefore everything was pushed upwards -- everthing was pushed from the bottom to the top" of the plane, he said.

The 228 people killed in the crash "had no time to prepare," he said.

But Bouillard said he did not have autopsy results from the bodies recovered, and did not know why no one lived through the crash.

"I don't know why nobody survived," he said. "I don't know the intensity of the impact. Perhaps we will find out from the autopsies. Perhaps we will never know."

Bouillard said it was still unclear what caused the crash, the deadliest in Air France's 75-year history.

"Today we are very far from establishing the causes of the accident," he said.

The plane was unable to fly on autopilot at the time of the crash, he added.

That was because the autopilot was not receiving speed, wind or direction information, he said.