WUHAN - Three workers died and four others are missing after scaffolding collapsed at a construction site in central China's Hubei Province, local authorities said Thursday.

The accident happened around 7 p.m. on Wednesday on the fifth storey of a building that was being constructed in Nanzhang County, according to the county government.

Twelve of the 13 workers were buried under concrete and debris.

As of 4:30 p.m., firefighters had rescued seven people, including two who died in hospital after emergency treatment failed. One other body was retrieved.

Rescue work continues to find the remaining four workers.

An investigation into the cause of the accident is under way.