Four units and 32 officials were held accountable for the landslide that killed 52 people and injured 30 on an expressway in Guangdong province in May last year; local disciplinary authorities announced the details on Saturday.

The Guangdong Provincial Department of Transportation, the Guangdong Provincial Highway Affairs Center, Guangdong Provincial Communication Group Co Ltd, and Meizhou Municipal Transportation Bureau were all ordered to issue written apologies.

Huang Chengzao, deputy director of the Guangdong Provincial Department of Transportation, was subject to reprimand and education and ordered a written apology.

Other officials have faced disciplinary actions or been admonished under Party and government regulations.

The Emergency Management Department of Guangdong Province said in a report released on Wednesday that the landslide occurred early on May 1 at the Chayang section of the Meizhou-Dabu Expressway, sending 23 vehicles tumbling and causing widespread devastation.

A monthslong investigation into the landslide determined that the cause of the serious disaster was prolonged heavy rain combined with multiple factors.