All passengers on board a Boeing 737 plane that crashed into a mountain in China this past week have been confirmed dead.

The airplane was operated by China Eastern Airlines, and was departing from China to Guangzhou. The plane was cruising around 29,000 feet and began it’s descent around 2:20 pm, falling more than 25,000 feet in about 2 minutes after an hour from their departure.

Richard Abouladia, Managing Director of Aerodynamic Advisory, said that “this kind of tragedy is extremely unusual.”

An air traffic controller tried to get in contact with the pilots after realizing that the plane was descending at an alarming rate. They could not get in contact with them, and the plane subsequently crashed not too long after that.

Seeing that there were no survivors from this specific flight, this makes it one of the worst crashes in all of aviation history. 120 of the 130 people on board had their DNA examined, and investigators are now trying to look for a cockpit voice recorder and other information to help them get a better picture of what exactly occurred before the crash.