After Tuesday's lightning strike, 12-year-old Chelal Matos' death in Virginia's Spotsylvania County brought the tally of lightning-related fatalities to six this year, including a woman who was killed by an indirect lightning strike in California last month.
Lightning is second only to floods as the deadliest natural threat, claiming about 58 lives each year, according to data from the National Weather Service. Yet the awesome electrical power of a lightning bolt, whether it hits a person directly or indirectly, can leave significant, lasting physical and mental damage, including burns, vision loss and personality changes.
"Lightning is a much larger problem than most people think," said Dr. Jonathan Adler, an attending physician in the Department of Emergency Medicine at Massachusetts General Hospital.
According to John Jensenius, a lightning safety expert at the National Oceanic and Atmospheric Administration, the average lightning bolt carries 20,000 to 30,000 amperes of charge and about 300 million volts.
A direct hit occurs when all of the lightning's energy is directed through the body or over the body on the skin. Although Adler said these kinds of strikes account for only 4 percent of all reported strikes, they are the most dangerous.
"When people are struck, current travels around the body, and sometimes people do surprisingly well, or through the body, which is a more severe injury and very broad," Adler said.
An intense shock can severely impair most of the body's vital functions. Cardiac arrest is common.
"Commonly, when there is a strike that affects the heart directly, there is a massive shutdown," Adler said. "With every beat the heart depolarizes and changes its electrical signal. The heart flat-lines ... and stays that way for some time."
In addition, Adler pointed out that the shock can temporarily paralyze the diaphragm and knock out circuits in the brain that instructs the body to breathe.
"If a person gets CPR right away they have a better chance of survival," Adler said.
But CPR must continue for a long time because it takes a long time for the heart to beat again, the diaphragm to function, and even longer for the brain to reboot and control vital organ functions. People who go into cardiac arrest have a 75 percent mortality rate.
Chelal received CPR from two nurses who were on the scene, according to First Sgt. Liz Scott of the Spotsylvania County Sheriff's Office, but he did not survive. A second boy who was walking close to Chelal when he was struck was also injured from the bolt, possibly through a secondary encounter.
Chelal's friend is still in critical condition, Scott said.
While direct hits are dangerous, secondary encounters are more common but can be just as perilous. Ground currents, which occur when lightning strikes an object or the ground and the electricity travels through the ground until it encounters another object, such as a person, make up about 50 percent of lightning injuries.
Another common way to be struck is through a side flash, or a splash, when lightning that has struck an object seeks a path that lets it jump through the air to a second object.