French prosecutors say the second black box from the Germanwings jet crash had been found — the data recorder that contains readings for nearly every instrument on the plane.

An official in Marseille Prosecutor Brice Robin’s office says he will give a news conference Thursday evening about the discovery.

If intact, the data is expected to provide crucial further evidence on the final moments of the flight in which the co-pilot is suspected of crashing the jet deliberately.

Investigators were also examining cellphones found in the debris of the jet crash for clues about what happened. A French reporter who says he saw such cellphone video described the excruciating sound of “screaming and screaming” as the plane flew full-speed into a mountain.

No video or audio from the cellphones of the 150 people aboard the plane who were killed in the March 24 crash has been released publicly. On Thursday, Lt. Col. Jean-Marc Menichini told The AP that search teams have found cellphones, but they haven’t been thoroughly examined yet. He would not elaborate.

Questions persist about journalist Frederic Helbert’s reports in the French magazine Paris-Match and in the German tabloid Bild this week about the video that he says he saw. Helbert vigorously defended his reports in an interview Thursday with The Associated Press.

Special mountain troops continued searching the area Thursday for personal belongings and the second black box flight recorder.

Helbert said he viewed the video thanks to an intermediary close to the investigation, but does not have a copy himself. The publications chose not to release the video, he said, “because it had no value regarding the investigation but it could have been something terrible for families.”

The video was shot from the back of the plane, he said, so “You cannot see their faces, but you can hear them screaming and screaming.”

“No one is moving or getting up,” he told the AP in Paris. “What was awful, what is imprinted in my memory, is the sound.”

“People understand something terrible is going to happen,” he said.

(AP)