A welder's torch sparked an explosion in an underground gas tank Friday evening, hurling a 1,000-pound asphalt chunk into the air that killed a passing driver, authorities said.

At least two others were injured in the blast, including the welder and a passenger in the victim's vehicle.

The explosion left a crater 5 to 6 feet deep and 15 to 20 feet across, and hurled chunks of asphalt and debris 100 to 200 yards, said Capt. Ronald Maybee (search) with the Jacksonville Fire Department (search). He said the underground tank was decades old.

"I've never seen anything like it," Maybee said.

Deputy Police Chief Paul Spring (search) said the blast occurred as the welder was trying to cut off vent pipes sticking out of the ground from the tank.