By Mike Hellgren

ABERDEEN, Md. (WJZ) — It will take days to clean up what’s left of the blimp that caused chaos after getting loose in Aberdeen. There are growing questions and concerns over how it broke free, coming close to crashing into homes and knocking out power to tens of thousands.

WJZ Investigator Mike Hellgren with what we know.

Just how that massive military blimp broke free in Maryland is now under federal investigation. WJZ has learned some local officials had long expressed concern this could happen, but were assured it was safely tethered.

You can hear the shotguns used to deflate the rest of the balloon. Parts have already been sent back to Maryland.

READ: State Police Using Shotguns To Deflate Wayward Blimp

It broke free from Aberdeen just after noon Wednesday before drifting more than 150 miles into rural Pennsylvania.

“I don’t want to speculate on any kind of cause,” an Army official said.

But the Army does not suspect foul play and tells WJZ the balloon was not undergoing maintenance at the time.

Raytheon, the manufacturer, once called the chance of it breaking free very small. A material called Vectran secured it, described as five times stronger than steel.

The blimp is part of a defense program that includes a second blimp in Baltimore County–both used powerful radar to detect missile threats.

The second blimp is not flying–for now.

“The investigation is going to show what happened, how it happened,” said Representative Dutch Ruppersberger, (D) Maryland. “This is unacceptable when we have a situation like this occur, and we need to hold individuals accountable.”

The $2.7 billion taxpayer funded program has already come under scrutiny in Washington, with some lawmakers calling it a waste of money–but not Ruppersberger.

“The Washington region, with Maryland, with D.C. and Virginia, is probably the number one target in the world,” Ruppersberger said.

“We did plan and have contingencies for a breakaway,” said an Army official.

Privately, some local authorities wonder why backup systems did not work, including one that was supposed to deflate the blimp the moment it became untethered.

Hellgren: “Do you expect to see that back flying above the skies of Maryland?”

Ruppersberger: “I’m going to be involved in this. Whatever it takes to protect our citizens, that’s what we’re going to do.”

That blimp is almost the size of a football field and was supposed to be able to hold up to hurricane force winds.

Two fighter jets followed the blimp during Wednesday’s incident.