Richard Hippel, a firefighter of 30 years' experience, has told the public inquiry about how he helped a trapped man from the blaze.
He and two colleagues went to the 16th floor, where "visibility was zero". They stumbled across resident Edward Daffarn, who was helped to the stairwell where he was able to escape. They believed it was likely he was the man they had been sent to help.
Mr Daffarn later asked to meet with firefighters at Kensington fire station in November.
Mr Hippel said in a written statement to the public inquiry: "He explained that he had come out of his flat, become disoriented in the thick smoke and had collapsed only a few seconds before CM (crew manager) Stern and I just happened to find him. He was incredibly lucky.
"Unfortunately, the man we had actually come up to find was the father of the young man, Sam, I had met in the doorway of the 16th floor lobby briefly.
"Mr Daffarn told me that Sam lived in a flat near his on the 16th floor with his father Joe, who was bed-bound, and that Sam had come down to ask for help getting his dad out.
"The full information didn't get through to CM Stern and myself as we just knew someone was on the 16th floor and trapped but not that they were in a flat and were bed-bound."
Mr Hippel said when he first checked the sixth floor he found it "completely filled with thick black smoke" - the first indication something was not right.
He said in the statement: "In nearly 30 years of service I have never seen smoke like that in a domestic property fire.
"The closest equivalent I can equate it to is the thick black smoke you get from car tyres as they burn."