Three young men and a toddler have been killed in three separate crashes around the country.
The 21-month-old girl died when she was hit by a car on Ardmore Walk in Tallaght, south Dublin, at approximately 5.30pm on Saturday.
She was taken to Tallaght Hospital where she was pronounced dead. The driver of the car was not injured.
In Sligo, a 22-year-old driver and his 20-year-old front seat passenger were killed when their car crashed on the Ballyfarnan to Sligo Road at Sooey at approximately 11.40pm.
The rear seat passenger, aged 21, sustained serious injuries and is in a stable condition in Sligo General hospital. Gardaí said both roads are closed while garda forensic collision investigators examine the scenes.
Police in the North also confirmed that 17-year-old Keelan Mullan died following a two-car collision.
The teenager, from the Drumsurn area of Limavady, suffered fatal injuries when his car, a silver Renault Clio, was in collision with a tractor on Drumsurn Road near the junction with the Cloghan Road at around 10.20am on Saturday.
The PSNI have appealed for anyone who saw the collision or either of the vehicles involved in the minutes prior to the collision to come forward.