"He was quite quiet, always polite ... wouldn't hurt a fly," Rosewarne said.
Mohammad Omar Faruk was excited to be a father. Many of their colleagues had been trying to reach out to Faruk's pregnant wife to express their condolences, he said.
"We are sorry for their loss," he said.
Last Friday morning the construction site had been too wet to continue working, so Faruk left around midday to pray at the mosque, he said.
At 1.40pm the attack on the mosques began with gunfire opened up indiscriminately on worshippers.
"We were all trying to get hold of him [on the phone] and he never responded," Rosewarne said.
Rosewarne returned to Christchurch Hospital, where the pair had been working on earthquake strengthening, to grab Faruk's tools on Monday.
"It felt empty me going there when I have had him working beside me these last three months," Rosewarne said.
"It felt really strange to be there without him.
"He will be greatly missed."