Two Austrian metalworkers were cooked to death in a smelting oven after a colleague switched it on while they were cleaning it.
Detectives said that the men had been slowly cooked in temperatures of up to 800C when the electronic door was closed on them. They vainly tried to claw their way out when their clothes caught fire.
Police said the men had completed the cleaning of the oven and had returned to it without informing colleagues or following safety procedures such as putting up a warning sign on the furnace.
The victims were a 56-year-old who had worked at the foundry for many years and a 49-year old who was on a temporary contract.
"Because of the intense heat at some point the men's clothes caught fire - and from there their bodies were burned," a police spokeswoman said.
"We are trying to work out how the door was closed and how [the oven] ended up being switched on. It could have been done manually or by remote control."