His screams reverberated around the factory floor.
They were so anguished and loud that they even jolted Chinese national Yan Wei Ming, 24, in the fishball factory's refrigerated room next door.
Rushing over to find out what had happened, he saw his colleague, Mr Sun Xiao Bo, 27, standing by the grinding machine with his head buried in his right arm.
Walking over, he saw a sight that made his blood turn cold - Mr Sun's left forearm was stuck in the grinder with blood dripping from it. The machine was still switched on.
His arm got stuck in the machine yesterday at about 8.25am, as Mr Sun, also a Chinese national, was grinding fish meat at Leong Hin Foods at 15, Woodlands Loop.
Another colleague called the Singapore Civil Defence Force (SCDF), which activated its Disaster Assistance and Rescue Team (Dart) .
A stunned Mr Yan told The New Paper that he immediately turned off the machine.
He said: "I didn't want to try to remove his arm as I was afraid I might do something wrong. We are not paramedics.
"I asked myself, 'How do I do this?'" Mr Yan said he tried to find a way to help Mr Sun, appealing to colleagues for assistance.
Mr Yan added: "He (Mr Sun) was sobbing.
I tried to comfort him, but he didn't say a word and just cried."