WMUR-TV reports the truck crashed on Interstate 93 in Bow, N.H., on Monday morning.
Emergency workers say the driver had a coughing fit and lost consciousness. His pickup truck went off the highway, hit a pole and then caught fire.
A state trooper witnessed the crash and stopped to help. The driver suffered bumps, bruises and possibly broken ribs.
Officials say a gun in the truck was discharging because of the heat of the fire.
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