MIAMI -

A U.S. airman from Florida was killed in a plane crash in Colombia while tracking a suspected smuggling vessel, the United States Southern Command said Wednesday.

Air Force Master Sgt. Martin Gonzales of Miramar was one of four killed on Saturday when the twin-engine turboprop crashed near the Panamanian border.

Also killed were two American defense contractors and Panamanian National Air-Naval Service Lt. Elroy Nunez. Two U.S. contractors on the plane who were rescued by Colombian military forces remain in stable condition in a hospital in Bogota after undergoing surgery.

The cause of the crash was not immediately known.

"Our hearts remain with the families of the men who lost their lives in this tragic crash," said Gen. John Kelly, Southcom commander. "It is a terrible tragedy, but we remain committed to finding out what happened and hopefully bring some sort of peace to the families."

Master Sgt. Gonzales, 39, was survived by his wife and two children.

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"He passed away very tragically while proudly serving for the US Air Force," his wife said in a statement. "He loved his job and was willing to risk his own life for others. He leaves behind two beautiful children, Nathan 7 and Kaitlyn 4. This is a very difficult time for our family. I still can't believe the plane my husband was in crashed and took his life. All I have left are memories of him. It's difficult to know that I will never see or hear his voice again. To me, he is an American hero!"

Southcom said the plane was contracted to provide detection and monitoring of drug trafficking routes in the coastal region of Central America as part of Operation Martillo (Hammer), a $165 million, U.S.-led regional security initiative that focuses on the seas off Central America, key shipping routes for 90 percent of the cocaine headed to the U.S. Fourteen countries participate: Belize, Canada, Colombia, Costa Rica, El Salvador, France, Guatemala, Honduras, the Netherlands, Nicaragua, Panama, Spain, United Kingdom and the United States. Chile has also contributed to the operation.

"Unfortunately he paid the ultimate cost and we're all very broken up about it," said Lt. Commander Ron Flanders.