Fears that a crane towering hundreds of metres above ground was not visible to aircraft in bad light were raised three months ago by a resident living in the shadow of the skyscraper.
James Harvard, 36, said that he told police in October that he could see no warning light on the crane.
Two people died and nine were injured when a helicopter hit the crane on St George Wharf Tower in thick fog and plunged to the ground this morning. The tower will be one of the tallest residential buildings in Europe.
The debris fell around a bus stop in Wandsworth Street, Vauxhall, causing panic among rush-hour crowds.
Harvard, a web developer, lives in Tradescant Road, just 800 yards from the St George Tower building site.
He told IBTimes UK that no light was visible on the crane which stands on the roof of the development more than 180 metres above street level.
"I happened to be looking out of the window late in the afternoon before. It was dark and it was misty. It stuck me that the crane did not have a light on it.
"Obviously, given that Battersea Heliport is close by, that concerned me. The next day I saw the Met Police had tweeted they were answering questions, so I got in touch and told them about it.
"A few days later I was walking in the street and I could see a light, but I thought it looked dim in comparison to others. Having already told the police I really did not think there was more I could do."
Developer Barclays denied that two navigation lights on the crane were not working when the helicopter hit. The navigation lights were checked the day before the crash, IBTimes UK was told.
Daily tests are carried out on the navigation lights, which also dot the outside of the huge glass tower.
The crane was hit by a 1970s-built lightweight twin-engine helicopter. The death toll could have been higher, but the crane driver was five minutes later for work.
Construction student Alan Zeligson was near the building when it was hit.
He told IBTimes UK: "The crane is one of the tallest cranes in Europe, and it's so high that it's tethered to the building and you have to go up 40 stories to get to the crane."
Harvard described the moment when the helicopter hit. He said it was "miracle" more people did not die.
"There was a bang followed by a splintering noise," he said.
"I looked at my watch and thought and thought it was the builders starting demolition work. But then it was eerily quiet and then two minutes later I started hearing sirens."
Harvard added: "I do wonder if I could have done more to kick up a fuss about the lighting. I thought I had left it in the hands of people better able to deal with it.
"It's a miracle that more people did not get killed because it's so busy there in the morning. It is right next to a bus stop and about 50 yards from one of the most busy rail lines in the country."