The lorry driver was waiting at the loading bay when a forklift suddenly reversed into him, pinning him against a concrete pillar.
As he cried out in agony, the forklift moved forward.
But before he could get out of the way, it backed into him again.
The victim, Mr T. Z. Yong, 34, is now in Tan Tock Seng Hospital's intensive care unit after the accident in the compound of Amtech Building at Sin Ming Road last Thursday.
He was talking to another worker while waiting for his lorry to be loaded with goods for delivery when the forklift, which was being driven by a man working for another company, hit him.
Mr Yong's boss, Mr Henry Ho, 30, who runs a logistics and transportation company operating from the compound, rushed to the scene after hearing about the accident.
He saw Mr Yong, a childhood friend, moaning in pain on the ground.
"There was a little blood and urine beside him. The moment I saw it, I knew it was jialat (Hokkien slang for big trouble).
"I was a medic in the army, so I have basic medical skills. I recognised right away that it was internal bleeding," Mr Ho told The New Paper yesterday.
Mr Yong's sister, Ms Cynthia Yong, 31, rushed to the hospital.
The advertising sales executive was joined later by their father, who lives in Johor Baru, Malaysia.
Recalling the harrowing experience, she said: "He was unconscious when I saw him and he was soon wheeled into the operating theatre. The doctor said the operation would take about two to three hours, but it took seven hours in the end."
Mr Yong had another operation last Friday, which lasted two hours.
An additional operation scheduled for yesterday was postponed. (See report above.)