The suicide bombers in Britain cooked up their explosives using mundane items like hair bleach. They stored them in a fancy commercial refrigerator that was out of place in their dingy flat. And cell phones were likely used to set them off.
Those details from the July 7 London subway and bus bombings emerged on Wednesday at an unusually wide-ranging briefing given by the New York Police Department to city business leaders.
The briefing -- based partly on information obtained by NYPD detectives who were dispatched to London to monitor the investigation -- was part of a programme designed to encourage more vigilance by private security at large hotels, Wall Street firms, storage facilities and other companies.
Police Commissioner Raymond Kelly warned that the materials and methods used in the London attack were easily adaptable to New York.
"Initially it was thought that perhaps the materials were high-end military explosives that were smuggled, but it turns out not to be the case," Kelly said. "It's more like these terrorists went to a hardware store or some beauty supply store."
The NYPD officials said investigators believe the bombers used a peroxide-based explosive called HMDT, or hexamethylene triperoxide diamine. HMDT can be made using ordinary ingredients like hydrogen peroxide (hair bleach), citric acid (a common food preservative) and heat tablets (sometimes used by the military for cooking).