Gardaí arrested the driver of a circus truck in Co Galway yesterday after an early morning traffic collision in which a mother and her daughter died.
A young man was also killed in a road crash early yesterday in north Cork when his car was involved in a head-on collision with a truck between Mallow and Charleville.
The three deaths brought to 107 the number of people killed on Irish roads to date this year.
In Co Galway, the two women who died have been named as Joan Reilly and her daughter Siobhán Reilly (25).
They were a mile from their home at Cloon, Co Galway, when the collision occurred at Cloonacauneen, near Corinthians Rugby Football Club on the N17 Galway-Tuam road, shortly before 6am.
Ms Reilly, a mother of five in her fifties, was driving her only daughter to work at the Merrit Medical Ireland Ltd in Parkmore, when their car was hit by a trailer which had become detached from a circus truck driving towards Claregalway on the N17.
The trailer was one of two being towed by the Circus Vegas truck, and contained crash barriers, according to gardaí.
The first trailer, which remained attached to the vehicle, was carrying several elephants, but the animals were not injured.
The trailer is reported to have jack-knifed, striking the Volkswagen Passat car and sending it across the road into a wall. Both women were killed instantly, gardaí said. There were no other cars on the road at the time.
The N17 between Tuam and Galway is one of the busiest and most hazardous approach roads to the city, and the collision was the third incident on the 40km stretch this week.
The shocked driver of the truck stopped at the scene, and fire brigade and ambulance personnel arrived within minutes, as a Garda sergeant on the way to work raised the alarm.
The bodies of the two women were taken by ambulance to University College Hospital, Galway.
The driver was being questioned yesterday at Mill Street Garda station under section 4 of the Criminal Justice Act.
Neighbours and friends of Ms Reilly's husband, John, a primary school teacher, and their four sons expressed shock at the circumstances yesterday as news of the tragedy spread through the village of Claregalway.
Siobhán Reilly's employer, Merrit Medical Ireland Ltd, remained closed for the day as a mark of respect.
Galway County Councillor Jim Cuddy (PD), a friend of the family, said it was a "great trauma to the whole area".
Gardaí said the collision was being fully investigated. The N17 between Parkmore and Claregalway was closed to traffic for much of yesterday as members of the Garda Traffic Investigation Unit inspected the scene.
This resulted in long tailbacks on a diversion to the city via Carnmore.
Gardaí in Cork were also investigating the collision which claimed the life of Mark Foley (21) of Limerick Road, Charleville, yesterday.
Mr Foley was driving from Mallow to Charleville when he was in collision with a bulk cement tanker.
He was killed instantly, and his body was removed to Cork University Hospital where a postmortem was carried out.
The driver of the lorry was not injured, but was treated for shock.