An unmanned drone aircraft fell from the sky and exploded by a Florida highway on Wednesday morning, snarling traffic and closing the road for the next 24 hours. According to a statement from Florida's Tyndall Air Force Base, State Highway 98 is closed "as a precautionary measure due to fires resulting from the crash and a small self-destruct charge carried on board the drone."

"An unmanned Air Force QF-4 drone, assigned here to the 53rd Weapons Evaluation Group, crashed on the drone runway during take-off at 8:25 a.m. today. No personnel were injured during the incident," the report said. "Base and local police and safety officials have closed Highway 98 and are anticipating that it will remain closed for up to 24 hours."

The stretch of highway -- which runs between the town of Mexico Beach and Panama City, Florida -- is closed because of the risk of fire in the acres of pine forest around Tyndall AFB, but also because of "a small self-destruct charge carried on board the drone."

"The status of this device is unknown," said the Air Force statement, "however, it is powered by a short-life battery which will be fully depleted in 24 hours," rendering the area safe.

A QF-4 drone is a larger aircraft than a standard RQ-170 spying drone. The QF-4 is a retrofitted F-4 Phantom jet. The Air Force uses the QF-4 drones as targets in weapons tests.

Panama City, Florida's WJHG Channel 7 reported that this is the second drone crash in the area in a week. The Air Force destroyed a drone in mid-air over the Gulf of Mexico, south of Cape San Blas. Vacationers on the Cape reported seeing the explosion when the drone detonated.

[image of QF-4 Drone in flight via]