One worker is missing and presumed dead and another worker was hospitalized after a natural gas well in southwestern Pennsylvania exploded and caught fire early Tuesday morning.

The well, owned by Chevron in Dunkard Township, Greene County, is about 50 miles south of Pittsburgh, in the Marcellus Shale region. It has been burning since the explosion, and officials say it might take days to get the fire under control.

The explosion occurred at 6:45 am Tuesday morning. First responders were able to assist with first aid and in evacuating the 18 other workers that were on the site at the time, but had to retreat immediately as the intense heat made it dangerous for people to be within 300 yards of the fire.

Despite having one of the most active gas drilling fields in the country, there are no personnel trained or equipped to deal with gas well fires or explosions. Chevron has flown in Wild Well Control out of Texas to begin developing a plan to extinguish the blaze.

State police have now set a half-mile perimeter around the site.

State officials are not sure what caused the explosions, and they say they will not know for sure until the fire is under control.

According to Chevron the well was drilled in 2012 and the hydraulic fracturing, or fracking, was completed last year. Chevron was in the process of connecting the well to its infrastructure of natural gas pipes as part of the final work of bringing the well into production.

This is not the first major accident at a natural gas well in Pennsylvania. According to the state’s Department of Environmental Protection, there have been at least 8 other fires, explosions or blowouts at wells since 2010, including one incident in which two workers were killed in Indiana Township in 2012 when the well they were working on exploded.

Pennsylvania Governor Tom Corbett has been a direct representative of the gas industry, promoting gas drilling and fracking, despite concerns over workers’ safety and the environmental impact, especially on drinking water.

The fracking process uses a soup of toxic chemicals to break up the shale rock bed that has trapped the natural gas. Those chemicals are then discharged into streams and rivers without adequate treatment. In addition, the fracking process also washes up tons of heavy metals that can find their way into ground and drinking water.

Sewage treatment facilities which process drinking water for population centers are now tasked with processing the toxic byproducts of the fracking process, even though the ability to safely treat these chemicals as well as their health impact is largely unknown.

Once the wells begin producing natural gas, there is the continuous danger that natural gas and methane can leak from the well, causing fires and poisoning nearby well water.

Under the Corbett administration, natural gas drilling and fracking has greatly expanded. Greene County has 641 wells, but five other counties have more. Corbett has rejected calls to impose any tax on gas extraction, a move that is costing the state hundreds of millions in lost revenue.

The administration also pushed through a law which removes local authorities from regulating or zoning fracking, which means that wells can be located next to schools, hospitals and water. That law has since been overturned in court, but the administration is fighting it. Even so, much of the damage has been done, and the Corbett administration is punishing communities that oppose drilling by only distributing impact fees to communities that permit the practice.

Allegheny County has gone so far as to lease drilling at the Pittsburgh International Airport and is in the process of leasing drilling at public parks.

In addition, the Corbett administration has signed a deal with Shell Oil to build a process plant in which the company will receive over $1.7 billion in tax breaks.

The gas companies have been direct supporters of public universities and in that way discourage research into the negative effects of the fracking process. Chevron itself is one of the largest donors, having funded the building that houses the chemistry department at the University of Pittsburgh, and contributed to building up Penn State’s oil and gas drilling engineering program to the point where it is now the largest outside of Texas.

The Obama Administration has thrown its support behind fracking, declaring the process necessary for national security. The Environmental Protection Agency has quashed investigations being conducted by its regional field offices into the impact of fracking.