SEOUL, South Korea (AP) — Three people were killed and three others were injured Tuesday when a decades-old overpass undergoing demolition partially collapsed in the South Korean capital, Seoul, fire officials said.

The accident occurred during a safety inspection after workers halted demolition work upon noticing that a part of the structure had slightly sunk while concrete slabs were being cut, said Lee Jong-woon, an official at Seoul’s Seodaemun District Fire Station. The victims were crushed by debris and other wreckage after a section of a bridge deck suddenly collapsed, officials said.