THREE men died from suspected smoke inhalation in a vacant house.
The men were found dead in the living room of the run-down property in Roscommon town. Gardai were called to St Ciaran's Park after a report of smoke at the house.
Fire crews were also called but there was no blaze to extinguish.
The three men, believed to be aged from their 20s to early 30s, had been using the house, which had been repossessed a number of years ago.
Fine Gael councillor Domnick Connolly knew one of the men.
"I was speaking to him just the other day," said Mr Connolly.
"They were all a friendly bunch who would have been well enough known around the town."
Fire chiefs and gardai were investigating whether a cushion or part of an armchair had been smouldering and the victims died from smoke inhalation.
It is understood the house, in the centre of the town, has been empty for up to three years and sits next door to another boarded-up property.
Locals have described the property as a squat and drinking den, and complaints have been made about glass bottles strewn at the back of the house.
All three men are believed to have been unemployed.
Roscommon Fire Service was called to the scene at around 7.30am.
Senior assistant chief fire officer Norbert Ferguson said gardai informed firefighters there was no need for their services and they were sent away.
"There was no fire and no smoke when we got there," said Mr Ferguson.
"That doesn't mean there hadn't been earlier in the morning, but there was certainly no visible damage to the house."
Mr Ferguson said the property had been sealed off by the time his crew arrived and there was no need for them to go inside.
He said: "It just looked like an ordinary house. Apart from the fact it was cordoned off, it looked like nothing had happened."
A Garda Technical Bureau team carried out forensic tests to try to establish how the men died.
Staff from the State Pathologist's office also attended the scene before the bodies were removed.
Gardai were first at the house after responding to a call informing them smoke was coming from the house.
Mr Connolly added that the town had been left devastated by the deaths.
"It is all everyone in the town is talking about this morning," said Mr Connolly.
"The details are still sketchy and we don't know who the men were, but Roscommon is a very close-knit town so it won't be long before we find out."
Mr Connolly said he was "absolutely shocked" when he heard the news.
"The town has been left sort of numb," he said.