Police in Thailand have charged two executives from a fire safety firm with negligence after a chemical accident killed eight people.
The incident occurred at the headquarters of the Siam Commercial Bank in Bangkok on Sunday night.
Contract workers were upgrading the fire extinguisher system when a chemical retardant was released, apparently suffocating them.
Police are investigating how the system was set off.
The executives, Adisorn Pokha and Napong Suksanguan, are from a firm called Mega Planet, which had contracted out the work.
They face up to 10 years in prison if found guilty of negligence.
Police Lt Gen Sanit Mahathaworn said they had expressed regret and were willing to pay compensation for damages, according to the Bangkok Post.
The bank had said that an aerosol system called pyrogen was "inadvertently activated and exhausted all the oxygen in the area" as contractors were working on it.
Pyrogen involves a mixture of gases including potassium carbonates, nitrogen, carbon dioxide, carbon monoxide, nitrogen oxide and ammonia. The system works by removing all oxygen from the air to stifle a fire.
Seven of those killed were contractors and one person was a bank security guard. Seven others were injured.