A man died and another was critically injured when they were overcome by toxic fumes while working in a sewer in Portmarnock on Wednesday.
The dead man, who has been named as Alan Harris, was working for his company Harris Draintech in the Drumnigh Wood housing estate on the outskirts of the north Dublin suburb when he and a colleague got into difficulties.
Emergency services were called to the scene.
Mr Harris, who sources say was in his mid-40s, was pronounced dead in the ambulance on the way to hospital.
The surviving worker remained in a critical condition on life support in Beaumont Hospital on Wednesday night.
Overcome by fumes
A spokesman for Dublin Fire Brigade said the workers were operating in a pit eight metres below surface level when one of them was overcome by the fumes and collapsed.
The second man lost consciousness as he attempted to resuscitate his colleague.
"The two men were at the bottom of the pit," said fire officer Gerry Stanley.
“They were retrieved with the help of a rope system to the surface but unfortunately one passed away.”
The Health and Safety Authority has confirmed that an investigation has begun into the incident.
Mr Harris was the owner of Clonee-based industrial cleaning service Draintech.
“He’s a really, really good guy. It’s a very sad time. Alan was Draintech,” said a source close to the family.