Kilstrom said they did not yet know the cause of the explosion.
"We just started the investigation this morning," he said. "Within the next couple days we should get to the facts, but you never know."
The explosion caused a residual fire. The Bancs Volunteer Fire Department, the Smithsburg Volunteer Fire Department and the West Union Volunteer Fire Department were all on the scene from about 4 a.m. until about 7 a.m. Sunday.
Kathy Cosco, a spokeswoman for the West Virginia Department of Environmental Protection, said that two inspectors with DEP's Office of Oil and Gas were at the site. A representative of the federal Occupational Safety and Health Administration was also on the site Sunday evening.
"It appears that what exploded was a tank at the site," Cosco said in an email.
Messages left with Antero Resources corporate headquarters and their West Virginia offices were not returned Sunday.
Antero Resources owns at least 399 wells in Doddridge, Harrison, Ritchie, Tyler and Upshur Counties, according to a 2012 DEP database. The database lists 141 of those wells as being actively drilled, although, because the database is incomplete, that number is likely higher.
Antero has had safety problems in the past. Last August a spark at an Antero-owned well in Harrison County ignited methane gas several hundred feet underground, causing a fireball and a fire that burned for about an hour. Three workers were injured in that fire.
DEP cited Antero for failure to maintain well control for that incident.
DEP has cited Antero for 17 violations of state code in the past three years. Those have been primarily environmental violations -- for things like failing to prevent waste runoff, failure to report discharges and contaminating waterways.
One violation, from January 4, 2013, warned, "Imminent danger water supplys [sic] threatened by allowing pollutants to escape and flow into the waters of the state."
In June of last year Antero was drilling using water in Harrison County when they accidentally repressurized some old water wells, causing several geysers, one about 10 feet high, that flooded one nearby home and several garages.
In March 2011, state regulators shut down an Antero gas well in Harrison County after mud contaminated with drilling chemicals spilled into a nearby stream.
Reach David Gutman at david.gut...@wvgazette.com or 304-348-5119.