SPANISH FORK — Michelle Pientka often finds lost wallets and purses. She picks them up and contacts the owner, hoping other people would do the same for her.

But on Tuesday, when Michelle, 21, and her younger sister Jessica Pientka, 16, picked up a black duffel bag abandoned in a Macey's shopping cart, she had no idea it was more valuable than any wallet or purse she'd ever found.

Inside the leather duffel, Michelle and her sister found a man's gym clothes, his wallet — and $17,811.

"It was all in cash with rubber bands around it in $100s and $50s," Michelle said. "They were big bills."

Across town, Ben Hunstman returned from the same Macey's and panicked when he realized his bag was missing.

At the store, his 2-year-old daughter wanted to ride in the basket, so he put the bag on the cart under the basket and unknowingly left it there when he drove away. He called police, went back to the Macey's and looked everywhere, but found nothing.

"I work for myself buying and selling cars," Hunstman said. "I'd just sold two cars that I'd purchased and sold and hadn't had time to get to the bank. … I didn't think I'd ever see (the bag) again. I was sick."

Hunstman was in luck. Michelle and her sister said they never dreamed of keeping any of his money. They only went through it to count it, mostly out of curiosity, and look for a wallet to identify the owner.

"I would feel guilty if I kept it," Michelle Pientka said. "Besides, I hope if I lost something someday, someone would return it to me."

Because of the amount of the money, Michelle Pientka called the police, who came, counted the money and took it with them.

Early Wednesday morning, as Hunstman was checking trash bins and garbage cans around town, a police officer called him with the news.

"You can't imagine the relief," Hunstman said. "I was almost hysterical."

When Hunstman collected the bag, nothing was missing. He later visited the sisters who had shocked him with their kindness.

"It just goes to show, you watch the news and you don't think there's good people anymore," Hunstman said. "But people surprise you. There's still good people."

Hunstman gave the girls a thank-you card and a reward of $250. Michelle Pientka said she's saving it for tuition at Utah Valley University, where she's studying nursing.