A Southwest Airlines flight headed to Dallas from Seattle was diverted after a human heart was found onboard the Sunday afternoon flight, the Seattle Times reported.
Someone forgot to unload a human heart, the flight's captain announced to passengers.
The heart, which had been on an earlier flight from Sacramento to Seattle, was not removed from the plane as it should have been.
How did the passengers react?
At first, some passengers were shocked over the news but the reaction quickly turned to kindness, Dr. Andrew Gottschalk told the Times because everyone "was happy to save a life."
Gottschalk said the horror began to sink in when those with internet began searching the internet and found that a heart would last only hours to be viable for transplant. Gottschalk is a physician in New Orleans who treats professional athletes.
It's not known whether or not someone's life was in danger because of the mishap or if the heart made it to its intended recipient, according to the report.
What did Southwest say?
Southwest spokesman Dan Landson confirmed to the newspaper that Flight 3606 landed at Sea-Tac International Airport after about three hours in flight, adding that the "life-critical cargo shipment" was removed from the plane.
The airline turned the flight around because it was "absolutely necessary to deliver the shipment to its destination in the Seattle area as quickly as possible," Landson said.
He said that the company that had shipped the organ specialized in "life critical" shipment but it would not provide the name of the business.
Are organs usually transferred by commercial airlines?
A spokeswoman for LifeCenter Northwest, an organization that facilitates organ transfers for the region, said they don't use commercial airlines for heart transplant transfers.
"We only use private flights," Katherine Pliska told the Times. "There's a time limit to get where it needs to go."
Many commercial airlines, including Southwest, ship organs intended for transplants and human remains to help them maximize revenue. However, these types of cargo account for less than 1 percent of Southwest's annual revenue, according to a previous report by the Dallas Business Journal.
Gottschalk described the incident as a "horrific story of gross negligence."
"The heart in question traveled from California to Washington, to the other side of Idaho, and back to Washington," he told the Times.
The flight's passengers deplaned in Seattle for an unrelated mechanical issue. Five hours later, they were back on their way to Texas.