New Delhi, July 3 -- BEIJING - His name was Liu. He was 66 years old, divorced, and living alone in a city of 22 million people when he made his final flight. He had suffered from anxiety for years. In his diary, investigators would later find, he had written about ending his life.

On the morning of June 28, Liu took off from a general aviation airfield in Pinggu district, on the northeastern edge of the capital. He was flying an Aurora SA60L, a small two-seat light-sport aircraft, under a private pilot licence he had obtained in 2024 after first qualifying as a sport pilot three years earlier. Within the hour, he had flown the aircraft into CITIC Tower, also known as China Zun, the country's tallest completed building at 528 metres, pla...