It was  your typical Salvation Army holiday setup: A pair of bell ringers outside a Walmart in Joplin, Mo., standing alongside your garden-variety kettle in which passers-by drop donations.

But what was later found among the usual mixture of donations was anything but ordinary.

Anonymous $50,000 Donation Left Inside Salvation Army Kettle in Joplin, Mo.

Image source: AP Photo/Nikki Fox

Salvation Army officials discovered tucked inside dollar bills five checks for $10,000 each as they tabbed their totals last Friday, noted ABC News.

Lt. Jamie Curry called the $50,000 donation “really exciting” and “a surprise sort of thing that you always hope for but can never count on.”

While unexpected, the anonymous act isn’t without precedent. The same large sum was donated last year, and similar donations have made their way into Salvation Army kettles over the last decade, totaling about $500,000 from what the charity calls its “Secret Santa,” ABC News added.

It’s unknown if the giving is from the same person, different individuals, or the result of a secret group effort. But whatever the source, the Salvation Army is understandably appreciative.

“It’s never the same person and our bell ringers can’t ever tell you who it was who put the money in because it’s usually wrapped in bills,” Curry told ABC News. “It’s always wrapped in a way that we would know it was from ‘Secret Santa.’”

“You can imagine how many people we’ve been able to help with all that,” she added.

The money supports clothing and housing programs, as well as meals for 200 to 400 people daily, Curry told ABC News.

“We have some members and longtime staff who have always tried to figure out who it is and who have their theories on who it could be,” she added. “For others, it’s kind of fun to just have the mystery. We like the idea of the anonymity and giving them the opportunity to be anonymous.”