There are fears over Olympic security after a known terror suspect entered the Olympic Park five times in a single day.
The British-born jihadist was arrested after breaching an order banning him from the area.
It's raised questions over security just days before the Games are due to begin.
More top news
The victim, who was also 15, was stabbed repeatedly just yards from the Capital City Academy School in Willesden.
Crossrail contractors have been hit with a fine of more than a million pounds over the death of a worker and other incidents.
Anh Nhu Nguyen, 52, claimed he lived in the North Kensington block and that his wife and son had died in the fire.