Mr. Swanton said authorities didn't yet know if the fire and the subsequent explosion was an accident or intentionally set, according to the Associated Press.

WSJ: Fertilizer-Plant Blast Kills Five to 15 in Texas

The subsequent explosion produced a tremor similar to a small earthquake.

BBC: Texas Waco fertiliser plant blast search for survivors

To be sure, at the plant site the radiation has spiked to deadly levels after the fire at one reactor and subsequent explosion at a different reactor.

FORBES: Tracking Radioactive Drift from Fukushima Nuclear Plant

The offshore drilling business has been in the headlines since the April 20th Deepwater Horizon explosion and subsequent oil spill.

FORBES: Go Offshore With Canadian Oil Sands

The feds say they intend to prove that BP was grossly negligent in causing the Deepwater Horizon explosion and subsequent spill.

FORBES: Dear BP: Please Don't Make Us Go Through This Again

The Department of Justice has filed a scathing brief accusing BP of gross negligence in the Deepwater Horizon explosion and subsequent 2010 Gulf of Mexico oil spill.

FORBES: Justice Dept Hammers BP For Gross Negligence In Gulf Oil Spill

It followed speculation that the Royal Ulster Constabulary (RUC) had intelligence before the explosion and made mistakes in its subsequent investigation of the atrocity.

BBC: Omagh relatives fight for truth