More Than 6,000 Feet of Tether Removed From Military Blimp Crash Site

— -- The tail section and detached tether portion of the blimp that caused an aerial "manhunt" on Wednesday have now been removed from the crash site, an official said.

The military blimp that somehow became untethered from an Army base in Maryland was a part of a test program launched by the Pentagon intended to detect drones and cruise missiles, officials said.

For much of today, the Army worked to destroy one of its own tools, as Capt. Matthew Villa, who is the J-LENS plans and coordination officer with the 263rd Army Air and Missile Defense Command, said that the Army used shotguns to shoot the blimp in an effort to speed up its deflation.

The number of rounds fired has not been released and there is an active investigation because officials still do not know how it broke away and why it partially deflated while on the loose.

Villa said that the tail section and 6,600 foot of tether were removed from the site this afternoon and removal work is expected to continue through Friday.

The blimp has an automatic deflation system designed to deflate the blimp should it go astray, but a NORAD spokesman said today it was unclear whether the system is what deflated the blimp to bring it down in Pennsylvania.

While some of the "critical" pieces of equipment at the scene have been removed, Villa told ABC News that 99 percent of the blimp's equipment is still at the cordoned-off crash site in Montour County, Pennsylvania.

Part of the reason why it has been so difficult to clear the site quickly is the nature of the terrain in the area. Villa said that there is a ravine near the heavily wooded area where the blimp landed, which is not helping matters.

The final plan for removing the blimp has not been finalized as officials weigh whether it will have to be airlifted or trucked out, Villa said.

ABC News' Luis Martinez and Mark Remillard contributed to this report.