By Elizabeth Hur

PHILADELPHIA (CBS) —  A big hunk of metal came flying through the roof of an office building and the workers there thought it fell off a plane!

The discovery was made Thursday morning at a Northeast Philadelphia shop and considering they’re located just north of Northeast Philadelphia Airport, their 911 call wasn’t taken lightly.

Stew Bridgewater with R.W. Hartnett recalled, “Police officials, fire department showed up. Homeland security, airport officials, and the FAA were here.”

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R.W. Hartnet is located in the 2000 block of Bennett Road. We’re told, it is the world’s oldest and largest company that manufactures printing equipment for pharmaceutical and candy industries. The damage done, as it turns out, wasn’t just the hole in the roof but also a machine — a prototype that took a year and a half to complete.

Bridgewater explained, “We were a week away from a customer accepting the machine and now we’ve got parts we’ve got to replace on it, big pieces, not just little tiny stuff.”

So what was the mystery metal piece that seemingly dropped from the sky?

For now, officials believe they’ve finally figured it out. It doesn’t appear to have fallen from a plane but they believe it flew from a neighboring yard a quarter-mile away!

Kyle Boyce with R.W. Hartnett Company said, “Turns out it was actually a chunk of metal off of one of the local mulching companies that’s here and they use it to grind up their mulch. It’s pretty crazy, one in a million, something you wouldn’t think but turns out it happened here. Everybody’s ok, that’s what’s good.”

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