The mystery of how wads of cash got strewn over a freeway in Hayward, sparking a frenzy of people to hop out on the road and collect the valuable green slips of paper, has been solved.

Family members, who asked not to be identified, told KTVU on Tuesday, that the money belonged to them. They had thrown $500 - all in $20 bills -- out of their car window on Monday afternoon onto southbound Interstate Highway 880 on their way back from a funeral.

It was to honor the man who died, they said, not wanting to add much more. It's an "Oakland thing," a relative told KTVU.

Folks on the freeway didn't know where the money was coming from, which appeared to be raining down like manna from the heavens. Dashcam video showed passersby snapping up the bills, left and right.

Hayward CHP Officer Manuel Leal told KTVU there were multiple calls about money blowing on the freeway. However, when officers arrived at the scene the money was gone.