The bizarre accident, which happened yesterday evening, reportedly killed both passengers inside the vehicle despite efforts to save them.

Social media footage of the incident, first reported today, showed rescue workers attempting to get inside the grey car as it lay on its side surrounded by broken glass and other debris.

Reports have said the vehicle was in a parking lot on the third or fifth floor of the company’s headquarters when the accident happened.

US-listed Nio did not respond to a request for comment and the cause of the accident was unclear.

A report by the Shanghai Securities News said the car was a model ET5, launched late last year to compete with rival Tesla’s popular Model 3.

Delivery of the model is slated for the third quarter of this year.

Last August, Lin Wenqin, a Chinese entrepreneur in Fujian province, died when his Nio sport utility vehicle crashed with the driver assistance function on, raising concerns about the safety of self-driving vehicles.