One man has died and two others have been taken to hospital after collapsing on a mushroom farm in Co Monaghan.
The three, in their 20s, were found unconscious at around 8pm last night in a silo at the plant near Emyvale.
One man was pronounced dead at the scene.
A post-mortem exam will take place today.
The two other men have been taken to Cavan General Hospital.
Two separate investigations are underway - one by the gardaí and the other by the HSA.
There are reports that investigators will look at the possibility the men were overcome by toxic fumes.