Manhole Explosions, Fire Rattle New York City Residents

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A fire underground led to manhole cover explosions that sent smoke billowing into the sky and terrified pedestrians near Port Authority Tuesday night. It happened near 38th Street and 8th Avenue. Eyewitness News' Lucy Yang reports

A series of powerful explosions and you can imagine the panic that shot through midtown as workers were jolted from the office buildings and traffic was snarled from all the street closures.

In the end, it turned out not to be the work of bombs, but of exploding manhole covers.

For a few frightening moments, people's minds raced to their worst fears: Another terror attack.

Witness: "The building shook tremendously. I was thinking the worst. I looked out my window, I wanted to see. I looked at the Empire State Building, I wanted to make sure it was okay."

Thankfully, their worst nightmares didn't come to pass.

Authorities report underground fires created such a pressure cooker under street level, that it sent five manhole covers flying into the air at the height of evening rush hour Tuesday.

The explosions were so intense, windows shattered. Several people were treated for loud ringing in their ears.

Thankfully, no one was seriously injured.

As firefighters put out the last of the green flames springing from the manholes, and as Con Ed began replacing their systems, workers went home tonight with a new blessing to count.

The exact cause of the fire and explosions is yet to be determined.