Gardaí and the Health and Safety Authority are investigating after a 26-year-old man died at a tunnel linked to the Corrib Gas project in Co Mayo.
It happened at Ah-Hoose near Pullathomas shortly before 9am this morning.
Operations at the tunnelling site have been suspended and a full investigation is now underway.
Gardaí say they're treating it as a "tragic incident".
Gardaí and Health and Safety are on the job," said Gerry Coyle, Fine Gael Councillor in Bellmullet, "and it will be their job to inform the next of kin overseas, and that's being done."
"It's a terrible tragedy … people are shocked that a young man could die in a tragic accident."