(NECN: Josh Brogadir, Portsmouth, N.H.) - The Sarah Long Bridge is closed and will be indefinitely so investigators can do a thorough check of its structure.
The disabled tanker remains at the state pier as officials take a closer look to find out what went wrong.
"It looked like the lines were starting to be strained and started to break one after another. And before I realized it once I came down to the state pier, the bow of the ship was out in the middle of the harbor," said Travis Jones, of Kittery, Maine.
The next thing Jones saw was the massive vessel - longer than a football field - strike the Sarah Long Bridge, the span that connects Portsmouth, N.H. to Kittery, Maine over the Piscataqua River along the Route 1 bypass.
"It was tied to the facility, something occurred that let the vessel drift away from the pier. We don't know if it was something mechanical in nature or otherwise, whether it was in the ship or on the pier we don't know yet," said Lt. Nick Barrow of the U.S. Coast Guard.
With the bridge deck down and cars going over at the time, it was fortunate that no one was hurt.
"When I was on the Kittery side it had just hit and then I came over and I was just watching it," said Natalie Landry of Portsmouth.
"It was completely parallel to it so that definitely didn't look right," said Mitch Hansen, on vacation from Dedham, Mass.
Hours later, once high tide had receded, tug boats moved the 473-foot Portuguese flagged tanker called the Harbor Feature back to the pier for a closer inspection.
They found a 20-foot long gouge in the stern, but nothing below the water line.
The living quarters are damaged and there is a hole in the bottom of the life boat from where it hit the bridge.
Coast Guard officials say the Harbor Feature can't hit the open seas again until that life boat is fixed.
The ship is carrying yellow grease and tallow oil, an animal byproduct and was in the harbor to refuel before setting sail.
"At this time there are no indications that any of those products have released in the water," Lt. Barrow said.
Since there is some structural damage to the bridge, it will remain closed indefinitely.
Travis Jones grew up with these ships, his uncles are on the tug boats helping assist, and he knows that a bad situation on the Piscataqua could have been worse.
"It's the third strongest current I think in the world, and it pulled the bow off the dock and it was all bad from there," Travis Jones said.
The center of the span on the lift bridge, was brought back down just after 6 p.m. It's supposed to be replaced in 2015.
There's serious concern about traffic because the Memorial Bridge is also closed, which is supposed to reopen in July, making the bridge over Interstate 95 the way to get around.