The muffled sound of a staircase collapsing at the Natural History Museum was followed by pandemonium, said museum visitor Katrine Dalsgard.
"I heard a noise - I was expecting a little thing," said Ms Dalsgard, from Denmark, who was on the museum's first floor with her husband and son when part of a limestone staircase fell.
"But from the first floor I saw people on the ground floor running towards the exit. I saw a young woman, very upset, crying, and I saw a mother calling her little children and running to the exit.
"We moved to the exit as quickly as possible."
Another witness, a teacher taking part in a course at the museum who would not give her name, said she heard "a loud bang and a lot of people shouting".
The first of 10 ambulances and five Dublin Fire Brigade units arrived within a few minutes, said witnesses.
Ambulance crews treated the wounded at the scene. One woman was placed in a neck brace and was treated in the guardhouse beside the museum gates, and crews eventually transported 10 people to three hospitals.
Some of those involved were able to walk away from the museum. About an hour after the accident, outside the museum's gates, an anxious John Moody was waiting for news of his daughter, a 24-year-old teacher from Clondalkin who had been taking part in a course inside the museum.
"My daughter and her friends were here on an educational trip. She just rang to tell me. I just flew here from work. She's all right," said Mr Moody.
It took about one hour for emergency workers to clear the injured, who were placed on spinal boards and taken to St James's Hospital, St Vincent's Hospital and the Mater Hospital.
The four patients who arrived at St James's suffered minor injuries, said Dr Patrick Plunkett, a consultant in emergency medicine at the hospital. He had expected more severe injuries.
"They looked bad when they came in," said Dr Plunkett.
"It could have been a disaster," he added. "We should have had very significant injuries but they will all be going home later today."