Police have filed negligence charges against two executives of a fire safety company after a system being installed at the headquarters of one of Thailand's largest banks malfunctioned, killing eight people.

The accident, which also left seven people injured, occurred Sunday evening in the basement of Siam Commercial Bank's headquarters in Bangkok, where a fire safety system was being upgraded.

Bangkok's acting police chief, Lt. Gen. Sanit Mahatavorn, said Tuesday that two executives from Megaplanet, the company contracted by the bank to install the system, face charges of negligence resulting in death. They face up to 10 years in prison if convicted.

The bank said that contractors had mistakenly activated the system and released a chemical known as Pyrogen, which deprives fire of oxygen.