http://www.sciencedaily.com/releases/2007/08/070829190807.htm...
ScienceDaily (Sep. 4, 2007)
"It was common fertilizer that Timothy McVeigh used to build the ferocious bomb that ripped into the Murrah Building, killing 167 innocent men, women, and especially children. Mixing ammonium nitrate with hate and fuel oil, McVeigh brought us a homegrown brand of terrorism and a raw grief from which we still reel.
Ammonium nitrate (AN) is a fertilizer used to create bumper crops. But, when combined with fuel oil (FO) it becomes ANFO, an explosive mixture of terrifying potential. The United States produces and imports millions of tons of it every year."