MIAMI (CBSMiami) – A foundering barge is now completely underwater 20 miles off the coast of Miami.

It towed by the Coast Guard into deep waters Wednesday morning where it safely sunk.

In the afternoon, photos from boats and planes monitoring the progress of the doomed barge show it standing up in the water, perpendicular to the waves, like a giant exclamation point. Many of the containers have fallen from the barge, and are in the water surrounding or are already headed to the bottom.

“The barge has flipped over and the stern is in the air, and we are monitoring the situation, helping to see if we can expedite the sinking of this barge,” said Capt. Chris Scraba, commander of Coast Guard Sector Miami.

The Coast Guard has been working with the barge and the tug that had been towing it for 3 days, after the tug Sante Tio lost power due to bad fuel.

That sent the tug and the barge, which is more than 200 feet long, adrift in heavy seas. The barge started taking on water, and spent much of the day Tuesday listing in the waves.

With the tug unable to tow the barge, the Coast Guard Cutter Seneca, returning to Massachusetts after a tour of duty in the Caribbean, stepped in as tow boat to keep the damaged barge and drifting tug from possibly sinking in the area South Florida’s coral reef.

The barge was towed into international waters, in an area about 2 thousand feet deep, well away from the reef. The Coast Guard worked with private salvage companies to sink the barge, after taking crew members off the barge Wednesday morning.

“It appears at least half the barge compartments have been compromised and their flooded.” Cory Offutt, owner of Tow Boat US Miami, told CBS4’s David Sutta as they flew over the scene Wednesday.

Salvage companies from across South Florida have tried to save it but in the end couldn’t.  “It’s pretty impressive that it’s still floating, ” Offut said. “It’s amazing the owner is going to lose his barge and his business.  It’s dramatic in a lot of different ways.”

“Back in the old days it probably would have been saved because they would have towed it into shallow water and they would have been able to work on it.  But because of all the environmental issues today the first thing they want to do is get it away from shore.” Offutt explained.

“We are working very closely with those partners as they put holes in the sides of the containers to make sure they sink safely at sea,” said Capt. Scraba.

Slideshow: Battle With The Sea

Scraba said there is no hazardous material aboard, just bare metal that will not be a hazard to the environment. Beyond saving the lives of crew members endangered by the drifting tug and barge, the Coast Guard was very concerned about the effect a sinking would have on the environment.

” By sinking the vessel out in 2 thousand feet of water,” Capt. Scaraba said, “we have done the best we can to ensure the environment is safe, and that there is no damage to the environment.”

Wednesday afternoon, it appeared the Coast Guard was going to help the barge on its trip to the bottom. “We need you to offset 10 miles off to the east or offset 10 miles to the west,” said a call over the Coast Guard radio channel.   “We are just going to be conducting some live fire exercises.”

The Coast Guard confirmed that it has worked with the shipping industry and the cruise ship lines based in Miami to make sure they were aware of the potential hazard to navigation.

The cause of the stranding is still under investigation, but the tug and barge began the trip in Haiti, and it’s there has been speculation the tug could have taken on contaminated fuel that fouled it’s engines.

The barge has been valued at $350 thousand.