David Oliver | USA TODAY

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Someone left a human heart in the cargo hold of a recent Southwest Airlines flight from Seattle, causing the Dallas-bound flight to turn around.

Like a mishandled bag, the human organ was mistakenly kept on the connecting flight. The heart was en route to an area tissue processor to recover valves for "future surgical procedures."

"There was no intended recipient," Sierra Donor Services spokesperson Deanna Santana said in a statement to USA TODAY Thursday. "While this gift was rerouted, it was received unharmed… to prepare the valves for future transplant."

Southwest described the Sunday evening incident in a statement to USA TODAY, referring to the transplant organ on Flight 3606 as "a life-critical cargo shipment" that was "intended to stay in Seattle for delivery to a local hospital."

However, the human heart was intended for LifeNet Health, a tissue processor in Renton, Washington, where a contracted courier ultimately transported the organ.

Despite the delay, the Seattle Times reported the heart was delivered 12 hours before it would have been unusable.

The "heart 'left on plane' reached its intended destination in time!" Santana added.

During the Sunday flight, the captain told the passengers about the heart to explain why the flight needed to redirect, saying the heart had been left on the plane following a previous flight from Sacramento, California, to Seattle.

"We made the decision to return to Seattle as it was absolutely necessary to deliver the shipment to its destination in the Seattle area as quickly as possible," Southwest said in a statement.

But that's not all: The flight also had an "unrelated mechanical issue."

"We brought in a different aircraft to continue the flight to Dallas, with an estimated delay of approximately five hours," the statement continued. "Nothing is more important to us than the Safety of our Customers and the safe delivery of the precious cargo we transport every day."

Dr. Andrew Gottschalk, who was on the flight, expressed his frustrations with the airline in a phone call with USA TODAY.

He accused the airline of lying that the shipment was "life-critical." He added the airline inconvenienced its passengers and treated them like cattle. He said he would like to hear Southwest say "We take responsibility for our actions."

Responding to Gottschalk's claims, Southwest told USA TODAY: "We acted on the information available to us at the time."

Contributing: Cydney Henderson, USA TODAY

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