For restaurant waitstaff, it must sometimes seem like the hottest food trend out there is to be allergic to something. However, as one Minnesota family’s lawsuit shows, not taking customers who say they have a food allergy seriously can have deadly consequences.

Last summer, the family of 16-year-old Scott Johnson headed to the Minnesota Nice Cafe in the small town of Bemidji, about three hours north of Minneapolis. Scott’s mom, Cindy Johnson, made sure to ask the server if the gluten-free pancakes on the menu were also dairy-free. According to the suit, the teenager had had a severe dairy allergy his entire life. Because of this, the family rarely ate out at restaurants, reported WCCO.

The server allegedly checked with the cook, who said the flapjacks were indeed dairy-free. Cindy Johnson told the server the grill would have to be cleaned before Scott’s pancakes were prepared—even trace amounts of dairy could make the teen sick—and the server agreed to let the kitchen know.

However, shortly after the teenage boy chowed down on two pancakes, he suffered an anaphylactic reaction. And he’d forgotten to bring his EpiPen to the restaurant.

Cindy Johnson rushed her son home so he could use the EpiPen, but his reaction was so severe that doctors said his heart stopped. Scott died three days later.

Scott’s dad, Steve Johnson, told WCCO he was working on a remote road construction site when he heard about what happened. “Hardest thing for me was I didn’t even get to talk to him,” he said.

The family has been overwhelmed by the amount they owe in medical bills, and they are suing to get Minnesota Nice Diner to pay their debts. The restaurant didn't immediately respond to an email request for comment, and has previously declined comment to other news outlets. The family also hopes that restaurants in general will begin to take food allergies more seriously.

Indeed, if you get a bunch of people who’ve worked in a restaurant together, the conversation will eventually turn to how picky some diners can be. There are those who want to change a dish so much—grilled instead of fried, and can you switch the sauce?—that what’s served doesn’t match what was originally on the menu. And as much as folks who have hopped on the gluten-free bandwagon without medical reason may seem annoying, Scott Johnson’s sad story reveals that a customer’s whims aren’t the same as having a legitmate allergy.

“Just one mistake can take someone’s life,” said Cindy Johnson.