A 21-year-old woman with a heart condition is dead after consuming a heavily caffeinated energy drink at Panera Bread that she may have believed was regular lemonade, her parents alleged in a wrongful death suit against the restaurant chain.

In September 2022, Sarah Katz suffered cardiac arrest after drinking “Charged Lemonade” at a restaurant with friends. She died after being transported to the hospital and suffering a second arrest, according to the lawsuit.

In addition to compensatory damages, Katz’s parents seek punitive damages as well.

“We were deeply saddened to hear about Sarah Katz’s tragic passing this morning, and our hearts go out to her family,” Panera said. “At Panera, we strongly believe in the transparency of our ingredients. This matter will be thoroughly investigated as soon as possible.”

Katz died from cardiac arrhythmia due to long QT syndrome (LQTS), according to the medical examiner. According to the Mayo Clinic, LQTS can cause fast, irregular heartbeats with life-threatening consequences.

The lawsuit claims Katz was diagnosed with LQTS when she was five years old and managed symptoms by taking medications and limiting caffeine.

Many energy drinks contain large amounts of caffeine, sugars, vitamins, including B vitamins, and other legal stimulants. Panera’s “Charged Lemonade” contains sugar, caffeine, coffee extract and guarana extract, both of which are caffeine sources. Dehydration, irregular heartbeats, and heart failure are some of the dangerous side effects associated with young people who consume energy drinks. The stimulating effects of these drinks could be more harmful to people who have certain heart conditions.