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
The world's largest annual flower show is celebrating 25 years. This year they expect more than 100,000 people to visit.
The graffiti was discovered the same say as an axeman smashed windows of a car parked outside a synagogue.
Two victims of serial rapist John Worboys were awarded compensation in the High Court for failures in the investigation into their attacks.