(Bloomberg) -- The investigation into Monday’s crash of a Boeing Co. 737-800 NG plane in China is under way, focusing on what made the aircraft suddenly drop from the sky.

There were 132 people on board the jet operated by China Eastern Airlines Corp., including 123 passengers and 9 crew. The plane went down in a mountainous area near the city of Wuzhou, according to the Civil Aviation Administration of China. Parts of the wreckage have been found.

China Eastern said it will ground all of its Boeing 737-800 jets starting Tuesday. An emergency telephone assistance line for family members was set up and the carrier expressed deep condolences to passengers and crew members onboard.

The airline’s website, mobile app and some of its social media platforms were turned to black and white in a sign of mourning.

China President Xi Jinping urged rescue efforts following the crash, state TV reported. 

We’re tracking the story, live.

Key Developments:

  • The jet was traveling from Kunming in Yunnan province to the manufacturing center of Guangzhou, according to FlightRadar24
  • Radar tracking shows the plane descended steeply on an almost vertical trajectory, with the aircraft disappearing off the flight tracker at 2:22:35pm local time on Monday
  • Video posted on social media purported to be from the crash site shows a fire in a heavily wooded area

U.S. Appoints Investigator (4:13pm New York)

The U.S. National Transportation Safety Board has appointed a senior investigator to work with China on its crash probe, the agency said in a tweet. In addition to its own experts, the NTSB will be assisted by representatives from Boeing and the U.S. Federal Aviation Administration.

Under a United Nations treaty, the country where a crash occurs takes the lead in an investigation, and representatives from the nation in which the plane and its components were built can participate.

Boeing, Supplier Decline (4:00pm New York)

Boeing’s shares fell 3.6% Monday as investors worried about fallout from the crash and subsequent investigation. The slide was the biggest in two weeks and nearly doubled its 2022 decline. While the China Eastern plane was not a 737 Max, the latest accident is renewing questions about the planemaker’s safety culture as the Max nears a possible return to commercial flights in China.

Spirit AeroSystems Holdings, which manufacturers large portions of Boeing airframes, dropped 3.5%.

Last Moments? (12:34pm New York)

Chinese media outlet The Paper posted a video it said was captured by a nearby mining company of the China Eastern jet dropping nose-first from the sky before disappearing over a ridge covered with dense vegetation. 

The aircraft in the video was intact on its way down, but too far away to show markings that would identify it as a China Eastern plane.

Paper said it verified the video with Beichen Mining Co., which does work in the area and installed cameras about 1 kilometer from the crash site. Bloomberg couldn’t independently verify the images.

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