Employees have returned to work at a General Motors metal-stamping plant in Marion following a chemical explosion that killed a contractor and injured several others.
GM spokeswoman Stephanie Jentgen said the plant's first-shift employees reported for work Wednesday morning at the plant about 60 miles northeast of Indianapolis.
The plant was evacuated following Tuesday's explosion involving a tank of chlorine dioxide that killed 48-year-old contractor James L. Gibson.
Jentgen said four workers injured in the blast were held for observation at a local hospital but have been released. She said an investigation into what caused the explosion is underway.
GM's website says the Marion plant employs about 1,600 workers and provides blanks, stampings and sheet-metal assemblies for vehicles to GM assembly plants across North America.
The explosion involved a chlorine dioxide tank, and the chemical continued spilling out after the explosion, Marion Fire Chief Paul David said. A hazardous materials crew contained the spill, and firefighters rinsed off the skin of everyone who came into contact with the chemical. If inhaled, the chemical can cause lung problems and can irritate the skin and eyes.
Marion Mayor Wayne Seybold went to the scene and talked with GM officials.
WRTV-TV reported that the Indiana Department of Labor cited the plant in December 2009 for a single serious safety violation. The plant paid a penalty of $845 and completed an abatement requirement. The plant has not had any violations since.