"Only chemicals freely available at hardware stores were then needed for the group to be able to replicate the formula used to make the bombs that killed 52 people - and four suicide bombers - in the attacks in London on July 7, senior investigators say."
Are we speaking of TATP, here? This is also what was used by Reid, the so-called "shoe bomber." It's also what was used by the so-called "lone suicide" Joel Hinrichs III, who blew himself up outside a stadium filled with 84,000 people attending a Sooners football game at OU.