Owners of giant rabbit threaten to sue United over its death

— -- The owners of a giant rabbit who died after a transcontinental United Airlines flight are threatening to sue the airline, their attorneys announced Monday.

The 3-foot long rabbit named Simon was going to be entered for the world's largest rabbit prize at the Iowa State Fair. According to the state fair's website, winners will receive $1,800.

Simon's owners claim his death has caused them "economic loss." It is unclear if the rabbit was shipped from the U.K. to the U.S. solely for the purpose of competing.

Simon was alive after his flight from London to Chicago last month but was found dead in his crate at United's PetSafe facility at O'Hare International Airport, according to the airline.

Guy Cook, the lead attorney for the three individuals who owned Simon, said they are demanding an independent investigation, reimbursement for the cost of transporting the potentially award-winning bunny and damages for their economic loss. It is unclear how much the owners paid to transport Simon or how much they are demanding in damages.

If United does not respond to the owners' letter within seven days, they said they plan to file suit.

"His death goes beyond the life of one single giant rabbit," said Cook.

"We're requesting that United Airlines reevaluate its policies with respect to the transportation of pets and ask that they take responsibility for this incident," he added.

Charles Hobart, a spokesperson for United Airlines, told ABC News the airline is saddened by the loss of Simon and is reviewing the letter from the attorneys.

Hobart added that United "takes its responsibilities in transporting pets seriously."

Some news reports claim the rabbit had died after United caretakers accidentally stored the rabbit in a freezer. United Airlines said these assertions are false.