A mystery drone rained money down on people enjoying a picnic in Rosa Parks Circle in Grand Rapids, Michigan, on May 26.
People started screaming with excitement while scurrying to grab $1 bills from the ground.
However, no one has yet stepped forward to claim responsibility for the philanthropic stunt.
Although police admitted the event looked “fun”, they said they should have been warned in advance because of safety concerns.
Sgt. Terry Dixon, from Grand Rapids Police Department, told Fox 17: “In a situation like this, this looks fun – fun for everyone involved – especially the kids that are out there. There’s money dropping from the sky and how often does that happen?
“The problem is that it could become a safety hazard for the kids or the youths that are running to get to the money – they could be crossing the roadway and inadvertently be struck by a car or something like that.”