Viewers of Prime Time on Thursday night found one part of the programme "difficult to watch."
The RTE current affairs show featured a report on the tragic deaths of four crew members of the Rescue 116 helicopter.
Rescue 116 crashed off Co Mayo at 12.46am on March 14, 2017 with four crew on board after it struck Blackrock Island 12 miles off the coast.
Captain Dara Fitzpatrick, the commander of the flight, was pulled from the sea in the hours after the crash and never regained consciousness, while the body of Captain Mark Duffy, the co-pilot, was taken from the cockpit 12 days later by Navy divers.
The bodies of winchmen Paul Ormsby and Ciaran Smith were never recovered despite weeks of intensive seabed, surface and shore searches.
Prime Time Investigates reporter Paul Murphy delivered a "heartbreaking" account on the tragedy ahead of a report being released on Friday.
The long-awaited Air Accident Investigation Unit report will detail the circumstances which led to the crash in 2017.
Inquests into the deaths of the crew had been postponed in 2018 to allow for the completion of the report.
Prime Time viewers were all saying the same thing on social media after the sad report on the deaths of the four crew.
Fine Gael TD Regina Doherty said: "Watching #rtept is heartbreaking tonight. The loss of life because of such careless multiple mistakes is so hard to fathom. #rescue116."
One viewer said: "Such tragic needless loss of life. Thinking of all the bereaved families tonight."
A second said: "That was heartbreaking, so many errors in the navigation systems, unnecessary deaths."
A third wrote: "So sad. Thinking of the families & friends who lost their loved ones."
Another person simply said: "#rescue116 is heartbreaking #rtept."
While one opined: "It's too soon, too raw, too recent. God help the bereaved families and friends."
Someone else stated: "This is difficult to watch. Thinking of all of the family and friends of the crew of R116 #rtept."
And another viewer added: "Oh wow! So sad to hear the circumstances that led to 4 deaths. Absolutely tragic miscommunications. #rtept."
