Children watched in horror as a hammer-wielding man went on a rampage in Naas General Hospital, smashing up a crowded Emergency Department.
The children were waiting with their parents when the attacker became "irritated" after having to wait to be treated.
A witness told the Herald that the man, believed to be aged in his 30s, left the crowded Emergency Department (ED) after complaining about the wait.
He then returned a few moments later carrying two hammers.
He began to threaten staff and smashed a number of windows and a glass door in the hospital before fleeing.
The incident occurred on Saturday at around 11.15pm.
"There were children present and they were cowering under chairs and very afraid," the witness said.
It is understood that some 20 people were waiting in the ED when the attack took place.
"People were hiding wherever they could once the man started smashing things up.
"There were children and adults hiding under chairs, locking themselves in the bathroom and even trying to get behind the vending machines.
"No one knew where to look because they didn't want to catch the man's eye."
The frenzied attack ended after about two minutes, the witness added.
Extensive damage was done to the department.
Several windows were smashed, as well as a glass door, and a number counters suffered damage.
The ED, however, remained open after the man fled the scene.
Following the incident, gardai confirmed that they were investigating a possible "incident of criminal damage that occurred at the hospital over the weekend".
"No arrests have been made but we are aware of the individual," a spokesperson said.
A local said the man involved in the attack was currently being held in a psychiatric ward.
Luckily, nobody was injured in the shocking incident.
In a statement, Naas General Hospital said it "regretted" any distress the incident might have caused patients.
"This matter is being investigated by the gardai," said a spokeswoman.
"The hospital regrets any distress which was caused to patients.
"We have no further comment to make regarding it."
Meanwhile the ED at Naas is among several that could be facing closure in the next 12 months.
While the Department of Health has stated that it has no plans yet to close emergency departments, a leaked report by the Trauma Steering Group has advised that emergency medicine in Ireland would benefit from increased centralisation.
The report lists nine hospitals where ED wards could be closed, and Naas General is among them.