No survivors have been found as the search continued Tuesday of the scattered wreckage of a China Eastern plane carrying 132 people that crashed a day earlier in a forested mountainous area in China's worst air disaster in a decade.

“Wreckage of the plane was found at the scene, but up until now, none of those aboard the plane with whom contact was lost have been found," state broadcaster CCTV said Tuesday morning, more than 18 hours after the crash.

The Boeing 737-800 crashed near the city of Wuzhou in the Guangxi region while flying from Kunming in the southwestern province of Yunnan to the industrial center of Guangzhou along the east coast. It ignited a fire big enough to be seen on NASA satellite images.

The crash created a deep pit in the mountainside, Xinhua news agency reported, citing rescuers. The report said drones and a manual search would be used to try to find the black boxes, which hold the flight data and cockpit voice recorders essential to crash investigations.

Also read: China Eastern plane crashed with 132 aboard

China Eastern Flight 5735 was traveling 455 knots (523 mph, 842 kph) at around 29,000 feet when it entered a steep and fast dive around 2:20 p.m. local time, according to data from flight-tracking website FlightRadar24.com. The plane plunged to 7,400 feet before briefly regaining about 1,200 feel in altitude, then dove again. The plane stopped transmitting data 96 seconds after starting to fall.

The plane was carrying 123 passengers and nine crew members, the Civil Aviation Administration of China said. It was about an hour into the flight, and nearing the point at which it would begin descending into Guangzhou, when it pitched downward.

Chinese President Xi Jinping called for an “all-out” rescue operation, as well as for an investigation into the crash and to ensure complete civil aviation safety.

At a hotel near the Kunming airport where the plane took off, about a dozen people, some in jackets identifying them as members of China's aviation agency, huddled around tables and read documents. Police and security guards at an airline office near the airport ordered journalists to leave.

State media reported all 737-800s in China Eastern’s fleet were ordered grounded. Aviation experts said it is unusual to ground an entire fleet of planes unless there is evidence of a problem with the model. China has more 737-800s than any other country — nearly 1,200 — and if identical planes at other Chinese airlines are grounded, it “could have a significant impact on domestic travel,” said aviation consultant IBA.

Boeing 737-800s have been flying since 1998, and Boeing has sold more than 5,100 of them. They have been involved in 22 accidents that damaged the planes beyond repair and killed 612 people, according to data compiled by the Aviation Safety Network, an arm of the Flight Safety Foundation.

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“There are thousands of them around the world. It’s certainly had an excellent safety record,” the foundation’s president, Hassan Shahidi, said of the 737-800.

The plane was not a Boeing 737 Max, the planes that were grounded worldwide for nearly two years after deadly crashes in 2018 and 2019.

China’s air-safety record has improved since the 1990s as air travel has grown dramatically with the rise of a burgeoning middle class. Before Monday, the last fatal crash of a Chinese airliner occurred in August 2010, when an Embraer ERJ 190-100 operated by Henan Airlines hit the ground short of the runway in the northeastern city of Yichun and caught fire. It carried 96 people and 44 of them died. Investigators blamed pilot error.

The U.S. National Transportation Safety Board said a senior investigator was chosen to help with the crash investigation. The U.S. Federal Aviation Administration, which certified the 737-800 in the 1990s, said it was ready to help in the investigation if asked.

Chicago-based Boeing Co. said it was in contact with the U.S. safety board “and our technical experts are prepared to assist with the investigation led by the Civil Aviation Administration of China.” The safety board said engine maker CFM, a joint venture between General Electric and France's Safran, would provide technical help on engine issues.

Crash investigations are usually led by officials in the country where the crash occurred, but they typically include the airplane’s manufacturer and the investigator or regulator in the manufacturer’s home country.

Shahidi said he expects investigators to comb through the maintenance history of the plane and its engines, the training and records of the pilots, air traffic control discussions and other topics.

Headquartered in Shanghai, China Eastern is one of the country’s top three airlines, serving 248 domestic and foreign destinations.

The aircraft was delivered to the airliner from Boeing in June 2015 and had been flying for more than six years. China Eastern Airlines uses the Boeing 737-800 as a workhorse of its fleet — the airline has more than 600 planes, and 109 are Boeing 737-800s.

The CAAC and China Eastern both said they had sent officials to the crash site in accordance with emergency measures.

China Eastern's website switched to a black-and-white homepage after the crash.

The twin-engine, single-aisle Boeing 737 in various versions has been flying for more than 50 years and is one of the world’s most popular planes for short and medium-haul flights.

The 737 Max, a later version, was grounded for about 20 months after two crashes in Indonesia and Ethiopia killed 346 people. China in December became the last major market to clear the Max to return to service, although Chinese airlines have not yet resumed flying the Max.

The deadliest crash involving a Boeing 737-800 came in January 2020, when Iran’s paramilitary Revolutionary Guard accidentally shot down a Ukraine International Airlines flight, killing all 176 people on board.