James Vaught, a retired Army lieutenant general who was best known for leading an unsuccessful attempt to rescue 53 U.S. hostages held in Iran in 1980, died Sept. 20 in Conway, S.C. He was 86.

The Horry County, S.C., coroner, Robert Edge, told the Associated Press that Vaught apparently drowned after falling into a pond from a pontoon boat. He also had signs of heart disease.

In November 1979, soon after Iranian militants seized the U.S. Embassy in Tehran, Vaught began planning a military operation to free the hostages. The rescue attempt became a defining moment of the presidency of Jimmy Carter, as the fate of the hostages loomed over the public imagination throughout the 1980 presidential campaign.

Vaught, then serving as the Army’s director of operations and mobilization, was the chief planner of a complicated mission dubbed Operation Eagle Claw. Personnel and equipment from the four major service branches were included in the effort, which required the coordination of Navy helicopters, Marine Corps pilots, Air Force transport planes and Army commandos. It was among the first engagements of an elite Army unit known as Delta Force.

The operation was set in motion on April 24, 1980, when eight Navy helicopters took off from the USS Nimitz, an aircraft carrier in the Persian Gulf.

There were obstacles from the beginning, including a communications blackout among the helicopters and a severe dust storm in the Iranian desert that caused one helicopter to turn around and return to the Nimitz.

Two other helicopters encountered mechanical problems, leaving only five capable of flying to Tehran. From the beginning, Vaught and other military planners had said that no fewer than six helicopters were required to carry out the mission.

Vaught and commanders on the ground recommended that the operation be called off. Carter agreed and made the final decision.

Soon afterward, the rotor blades of a helicopter attempting to refuel at a staging area in Iran struck an Air Force transport plane. Eight U.S. service members died in the fiery accident. The wreckage was left in the desert, along with secret information aboard the aircraft.

Military observers considered Operation Eagle Claw a colossal failure, and several congressional and military investigations were launched.

Years later, Vaught said he was hampered by turf battles among the military branches. When he asked to inspect the Navy helicopters before the mission, he said, permission was denied.

“I was told it was the Navy’s job, and it was perfectly capable of preparing and repairing them,” he told the Tampa Tribune in 2005. “I had no authority except over the Army guys.”

The botched rescue effort was one of the lowest points of Carter’s presidency and became an issue in the 1980 presidential election, which Carter lost to Ronald Reagan.

One hostage was released because of illness in July 1980. The remaining 52 hostages were freed Jan. 20, 1981, the day Reagan took office.

Over time, Vaught came to view the hostage-rescue effort as a “successful failure” because it exposed flaws in military planning and led to a variety of reforms.

He recommended the creation of a joint special-forces unit that would cover all branches of the military. The combined U.S. Special Operations Command was launched in 1987.