Rescuers scoured heavily forested mountain slopes in southern China on Tuesday looking for victims and flight recorders from a China Eastern Airlines (600115.SS) passenger jet that crashed with 132 people on board.

State media said parts of the Boeing 737-800 were strewn among trees charred by fire after China’s first crash of a commercial jetliner since 2010. Burnt remains of identity cards and wallets were also seen.

Flight MU5735 was travelling to the port city of Guangzhou from Kunming, capital of the southwestern province of Yunnan, when it suddenly plunged from cruising altitude and crashed in the mountains of Guangxi less than an hour before it was due to land.

Chinese media carried brief highway video images from a vehicle’s dashboard camera that appeared to show a jet diving to the ground at an angle of about 35 degrees from the vertical.

Reuters could not immediately verify the footage.

Si, 64, a villager near the crash site who declined to give his first name, told Reuters he heard a “bang, bang” at the time of the crash.

“It was like thunder,” he said.

State media, which described the situation as “grim”, have said the possibility of the deaths of all on board could not be ruled out.

The crash site was hemmed in by mountains on three sides, state media said, with just one tiny path providing access.

Rain was forecast in the area this week. Excavators were clearing a path to the site, images on state television showed.

Earlier, video images from the People’s Daily, the official newspaper of the ruling Communist Party, showed search and rescue workers and paramilitary forces scaling tree-covered hillocks and placing markers wherever debris was found.

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Police set up a checkpoint at Lu village, on the approach to the site, and barred journalists from entering.

Several people gathered near the crash site on Tuesday for a small Buddhist ceremony.

An investigation team sent by the State Council, or cabinet, will give details of the search and rescue effort and the hunt for the black boxes at a news conference later on Tuesday, state television said.

The last commercial jetliner to crash in China was in 2010, when an Embraer E-190 regional jet flown by Henan Airlines went down, killing 44 of the 96 aboard.

Highlighting the top-level concern, Vice Premier Liu He went to Guangxi on Monday night to oversee search and rescue operations.

The disaster came as plane maker Boeing (BA.N) seeks to rebound from several crises, notably the impact of the coronavirus pandemic on air travel and safety concerns over its 737 MAX model following two deadly crashes.

Once it is found, the cockpit voice recorder could yield clues to what went wrong with Monday’s flight.

“Accidents that start at cruise altitude are usually caused by weather, deliberate sabotage, or pilot error,” Dan Elwell, a former head of U.S. regulator the Federal Aviation Administration, told Reuters.

Elwell, who led the FAA during the 737-MAX crisis, said mechanical failures in modern commercial jets were rare at cruise altitude.

The U.S. National Transportation Safety Board (NTSB) on Monday appointed an investigator, as the Boeing aircraft was produced in the United States, but it was unclear if the investigator would travel to China.

On Monday, China Eastern and two subsidiaries grounded its fleet of 737-800 planes. The group has 225 of the aircraft, data from British aviation consultancy IBA shows.

As of Tuesday, other Chinese airlines had yet to cancel any flights that use 737-800 aircraft, according to data from Chinese aviation data provider Flight Master.

Among the passengers on flight MU5735 was the chief financial officer of Dinglong Culture (002502.SZ), a Guangzhou-headquartered firm whose businesses range from entertainment to titanium mining.

A provincial daily cited a woman as saying six of her family members and friends were on the flight to Guangzhou, where they had been due to attend a funeral.

The Star