One collision that occurred on the N7 at Rathcoole when a car travelling on the wrong side of the road collided with a truck at approximately 11.40pm last night on the northbound carriageway between Citywest and Baldonnell.
Three men were killed when the car burst into flames upon impact with the lorry.
The driver of the lorry was taken to University Hospital Tallaght with serious injuries to his legs.
SundayWorld.com understands that just minutes before the horror collision, gardai had observed the BMW car that the three men were travelling in driving erratically in the Cheeverstown area of west Dublin.
Sources say that offcers attempted to interact with the vehicle but it sped away and a short pursuit began.
As the car involved in this collision had come to the attention of Gardaí prior to the incident, An Garda Síochána Ombudsman Commission (GSOC) have been notified.
Gardaí are appealing, in particular, for any witnesses who may have seen a dark blue BMW 3 Series vehicle (06-D-47768) in the areas of Belgard, Citywest or the N7 between 11.15pm – 12am to come forward.
Gardaí can be contacted at Clondalkin Garda station on 01 6667600 or the Garda Confidential Line on 1800 666 111.
Gardai said post-mortems on the deceased will take place later this afternoon.
Separately, gardaí are also appealing for witnesses to another horror crash on the Ross Road in Killarney, Co Kerry on Wednesday that claimed the life of a 14-year-old boy.
Thomas Healy from the Gap of Dunloe, Beaufort, died when the car he was driving crashed on the Ross Road near Killarney shortly after 1am.
A passenger in the car, also a male youth in his teens, was later taken to Kerry University Hospital to receive treatment. He remains in a serious but stable condition.
The vehicle was subject to interaction with Gardaí prior to the collision. As such the matter has been referred to GSOC.
Gardaí are asking anyone who may have saw a 95-KY reg, Green Toyota Corolla Saloon in Killarney Town between 12.45am – 1.15am on Wednesday morning to come forward to them.
Anyone who may have dash cam footage is also asked to make this available to gardaí and they can contact them at Killarney Garda Station on 064 6671160 or the Garda Confidential Line on 1800 666 111.