Speaking to the Evening Standard, Zeba Begun, whose house overlooks the scene where the woman died said:
"She then looked to her left and then to her right and I had no idea what she was going to do, I thought maybe she was joking about, but then about 30 seconds later I heard some beeps from the oncoming traffic which could see her.
"And she just waved at the traffic and then fell down onto the road. As soon as I saw it I called the ambulance and police."
More top news
West Ham have opened an investigation into a flyer that was allegedly distributed ahead of the game with Chelsea.
Damon Joseph Smith smiled and waved at his mother, who waved back.
Tanguy Marie De Carne, 53, jumped red traffic lights and rode on busy pavements through the City pursued by police