The pilot who died after crashing a small plane into Beijing’s tallest skyscraper, injuring 13 people, had mental health issues and had written about suicide in his diary, authorities said on Thursday.

The 66-year-old man flew a light aircraft into the 528-metre CITIC Tower in Beijing’s Central Business District on Friday at 5:55pm local time.

The plane crash raised questions about aviation safety in tightly secured Beijing, with the CITIC skyscraper around seven kilometres (4.3 miles) away from Zhongnanhai, the government compound which houses top Chinese leaders.

AFP journalists at the scene had seen a hole in the window of one of the building’s upper floors, with witnesses reporting plane debris and a small fire at the foot of the tower.

The pilot — surnamed Liu — was divorced, lived alone in Beijing and “had long suffered from insomnia and anxiety, and his diary contained multiple references to ‘ending his life’”, the capital’s Chaoyang district government said in a statement.

“This was an incident endangering public safety caused by personal reasons,” it added.

Liu worked as a freelancer and had obtained a sport pilot licence in 2021 and a private pilot licence in 2024, according to the statement.

On the afternoon of the incident, Liu took off from a general aviation airport in suburban Pinggu district and conducted both supervised and solo flights, the statement said.

During his last solo flight, Liu “deviated from the designated area and lost contact with the airport” before the crash, it added.

He was flying a two-seat propeller-driven light aircraft.

Chinese social media was rapidly scrubbed of photos and videos of the plane crash shortly after it took place, while police at the scene stopped journalists and onlookers from taking pictures of the building.