SCOTTSBURG, Ind. — A customer’s act of kindness in the drive-thru ended up sparking a chain reaction of goodwill at a southern Indiana McDonald’s.

Hunter Hostetler, a cashier at the restaurant, said an older woman waiting in the restaurant’s drive-thru Sunday decided to pay for a large order for the van behind her in line as a kind gesture for Father’s Day. A man and four children were inside the van. They’d ordered “a bunch of Happy Meals, two Quarter Pounders, a Big Mac meal” and some other items, Hostetler told WDRB.

The woman told Hostetler to wish the man a “Happy Father’s Day” before paying for the order and driving off.

That would’ve been a heartwarming story in its own right. However, the dad in the van didn’t just take his food and run. Instead, he paid for the orders for a couple cars behind him in line.

The idea spread like wildfire, quickly becoming 10 drivers, then 20, and so on. By the time all was said and done, 167 customers decided to pay it forward from 8:30 p.m. to midnight at the drive-thru.

Hostetler said everyone was on pins and needles wondering how long it would last.

“I had people telling me, ‘No, it’s going to stop here, It’s going to stop at 100. You’re not going to make it past [that],'” he said.

The pay-it-forward chain included Abby Smith, who was in car number 161 with her boyfriend. She told WDRB that it’s a “great feeling to know that there’s a lot of great people out there.”