I kinda doubt it... there's a company that manufactures oil rigs located about 200 yards south of that bridge... a far more plausible source.
They just stated on FoxNews that it is a floatel, a floating dormatory for the oil workers and that it had been washed away from the shipyard where it had just been constructed. While it can be towed by just one tugboat, they are sending several of them to pull it away from the bridge.