Vacaville, Calif. -

This story may restore your faith in humanity.

Firefighters in Vacaville, Calif., were grabbing some groceries at a local Costco over Memorial Day Weekend when they had to leave the store on an emergency call.

They couldn't get to the cashier in time, so they left the groceries behind. When they returned, they found their goods waiting for them, they also found a receipt: Someone had paid their $123 bill.

"Thanks for being there for us," the receipt read. "Have a good weekend." It was signed, "Air Force Wife." The firefighters didn't meet the woman, so they used their Facebook page to say thank you.