"The explosion left a crater 93 feet wide and 10 feet deep," Fernandez writes. "Ten of the 15 people killed were volunteer firefighters and other emergency workers; more than 260 others were injured. Of the town’s 700 homes, about 350 were affected, including 193 that were destroyed or severely damaged. Three schools, a nursing home and a 50-unit apartment complex were destroyed or heavily damaged."
"The type of agricultural chemical that set off the explosion—ammonium nitrate—was sold at the plant to farmers for use as a fertilizer," Fernandez writes. "In normal storage conditions, ammonium nitrate is difficult to ignite, but intense heat and other unusual conditions can cause it to detonate. It was used by Timothy J. McVeigh in the Oklahoma City bombing in 1995."