A massive blast flattened a fertilizer plant as emergency medical and fire personnel and responded to a fire at the plant in the town of 2,800. At least two of the dead are believed to be first responders.
A huge boom that witnesses said echoed for miles was heard as the explosion leveled West Fertilizer Co., badly damaged a 50-unit apartment complex and at least 50 homes in a five-block area, according to a CNN report.
The explosion, which was ignited by a fire at the plant, registered as a magnitude 2.1 seismic event, according to the U.S. Geological Survey.
Editor's note: This article was updated on April 22.