oil rig mapStill reeling from the devastation caused by the explosion of BP's Deepwater Horizon rig, the U.S. got another scare Thursday as the Coast Guard responded to another rig explosion in the Gulf of Mexico.

The accident, which happened at 9:30 a.m., took place 80 miles south of Vermillion Bay off Louisiana on the Vermillion Oil rig 380, which is owned by Houston-based Mariner Energy (ME). Shares of Mariner initially dropped more than 4%, before recovering some ground, as reports of the explosion reached news outlets. Shares of Apache (APA), which is expected to buy Mariner Energy, also fell more than 1%.

According to CNN, and contrary to earlier reports, there were 13 workers on board the rig. Twelve of them were rescued in the water and one person is injured.

A Mariner spokesman told CNBC that there "doesn't appear that there is any spill or sheen to be seen on the water" following the fire. He explained that the fire happened away from any areas involved in oil production and said the facility isn't a drilling rig, but rather a production facility.

The news is the latest scare for the Gulf region involving offshore oil rigs. On April 20, Transocean's (RIG) Deepwater Horizon rig, which was being leased by BP (BP), exploded as the Macondo well in the Gulf blew out, causing a massive oil spill that took more than two months to contain. Eleven crew members died in the explosion.

Increase your money and finance knowledge from home

Understanding Stock Market Indexes

What does it mean when people say "the market is up 2%"?

View Course »

Asset Allocation

Learn the most important step in structuring an investment portfolio.

View Course »