In November 2014, a worker was overcome at a DuPont chemical manufacturing facility when a supply line unexpectedly released more than 20,000 lbs. of methyl mercaptan, a deadly chemical. Three co-workers came to the worker's aid in an attempted rescue, but all four were asphyxiated fatally by the colorless, flammable, and highly toxic gas.

After the initial investigation into the four deaths, OSHA found hazards that prompted the inspection at the facility to be expanded under the National Emphasis Program for chemical facilities.