A massive explosion at a fertilizer plant in Texas leveled a four-block area and sent a mushroom cloud into the sky. Authorities say between 5 and 15 are dead and more than 160 injured. It's not known how the initial fire started last night at the West Fertilizer Company plant in West, Texas. Amateur video shows the fire raging then a powerful explosion that registered as a small earthquake.

Here's the audio of the dispatch call:

The town uses volunteer firefighters - three to five are missing after responding to the emergency. According to the Associated Press, the plant was cited in 2006 by the Texas Commission on Environmental Quality for failing to obtain or to qualify for a permit - the citation came after a complaint about strong ammonia odor. Explosions at fertilizer plants are rare. In 2001, a similar plant in Toulouse, France killed 31 and injured more than 2,000.

How are firefighters trained to handle chemical accidents? Do volunteer firefighters have the same expertise? How common or rare are industrial explosions? Should there be a wide perimeter around such plants prohibiting residential buildings?

Guest:

Rick Jervis, Staff Reporter, USA Today reporter from West, Texas