Athens, Greece ? The last man conscious in the cockpit of a doomed Cypriot airliner made a desperate call for help – “Mayday! Mayday!” – two seconds before the plane carrying 121 people smashed into a mountain near Athens.

The man, apparently a flight attendant with pilot training, twice issued distress calls in the final 10 minutes of Helios Airways Flight 522, chief investigator Akrivos Tsolakis told The Associated Press on Monday.

“The second time was a couple of seconds before the crash,” Tsolakis said, adding the man had “a very weak tone of voice.”

Earlier Monday, Tsolakis issued a preliminary report on the Aug. 14 crash, which killed all 115 passengers and six crew, that said the Boeing 737-300 lost cabin pressure and eventually ran out of fuel.

The report was the most comprehensive statement the government has released on the investigation since the crash. It came after pressure from the media and the airline industry for Greece and Cyprus to start answering questions about what caused the accident.

Still, it remained unclear what caused the loss of cabin pressure. Greek investigators, aided by the U.S. National Transportation Safety Board, are continuing to probe the crash, the deadliest airline disaster for Greece and Cyprus and considered one of the most baffling in aviation history.

Tsolakis presented his initial findings following analysis of flight recorders and autopsies on all 118 bodies – many still unidentified – recovered from the site. Three bodies have not been found, including that of the plane’s pilot, a German.

The report appears to confirm initial suspicions that people aboard the Helios Airways plane were incapacitated by a loss of cabin pressure early in the flight at about 34,000 feet and that someone tried to save the flight shortly before it crashed.

According to the report issued Monday, a man wearing an oxygen mask, believed to be 25-year-old flight attendant Andreas Prodromou, tried to steer the plane for the last 10 minutes and contact air-traffic control authorities.

In his first appeal, he cried “Mayday!” three times – but the plane’s communications had apparently been set to the wrong frequency, Tsolakis said.