Last year, a truck carrying drilling water in Clarksburg, West Virginia, overturned onto a car carrying a mother and her two boys. Both children, 7-year-old Nicholas Mazzei-Saum and 8-year-old Alexander, were killed.
"We buried them in the same casket," recalled their father, William Saum. He said his wife, Lucretia Mazzei, has been hospitalized four times over the last year for depression.
Traffic fatalities in West Virginia's most heavily drilled counties, including where the Mazzei-Saum boys were killed, rose 42 percent in 2013. Traffic deaths in the rest of the state declined 8 percent.
The average rate of deaths per 100,000 people—a key mortality measurement that accounts for population growth—in North Dakota drilling areas climbed 148 percent on average from 2009 to 2013, compared with the average of the previous five years, the AP found. In the rest of the state, deaths per 100,000 people fell 1 percent over the same period.
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Traffic fatalities in Pennsylvania drilling counties rose 4 percent over that time frame, while in the rest of the state they fell 19 percent. New Mexico's traffic fatalities fell 29 percent, except in drilling counties, where they only fell 5 percent.
In 21 Texas counties where drilling has recently expanded, deaths per 100,000 people are up an average of 18 percent. In the rest of Texas, they are down by 20 percent.
For Villanueva, that means there are now accidents serious enough to require air transport of victims three or four times each week, compared with only a few times a month before drilling operations took off.
Some experts say regulatory loopholes contribute to the problem. Federal rules governing how long truckers can stay on the road are less stringent for drivers in the oil and gas industry.
Every truck accident "is a tragedy," said Steve Everley of the industry group Energy in Depth. He said oil and gas drillers and their suppliers have been working to reduce traffic and accidents by adopting safety programs, recycling more drilling water and building more pipelines for water.
Vehicle crashes are the single biggest cause of fatalities to oil and gas workers, according to a study by the National Institute for Occupational Safety and Health.
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Some states are working to reverse the trend by widening roads or promoting safer driving.
On the day his sons were killed, William Saum's wife had taken the boys to the YMCA to register for swimming and karate classes. The truck didn't stop at the stop sign, tried to make a turn and flipped onto the family car. Police issued two traffic tickets but filed no criminal charges.
Asked what he thinks of the drilling boom, he paused.
"I guess," Saum said, "it's good for the people who are making the money."
—By The Associated Press