(NewsNation) — The parents of a college student with a heart condition who died after drinking Panera Bread’s “Charged Lemonade” are now suing the company.

A legal complaint, first obtained and reported on by NBC News, says the “dangerous” beverage contained more caffeine than one can of Red Bull and one can of Monster energy drink combined.

Filed Monday by Sarah Katz’s parents in the Philadelphia Court of Common Pleas, the lawsuit alleges Panera did not appropriately warn consumers about the ingredients in the “charged lemonade.”

NewsNation reached out to Panera for comment, but did not hear back.

The company told CNN in a statement, “We were very saddened to learn this morning about the tragic passing of Sarah Katz, and our hearts go out to her family. At Panera, we strongly believe in transparency around our ingredients. We will work quickly to thoroughly investigate this matter.”

Katz, a 21-year-old studying international relations and health at the University of Pennsylvania, with a minor in East Asian languages and civilizations, was diagnosed with Long QT Type 1 Syndrome, or LQT1 when she was five, the lawsuit says.

LQTs, according to the American Heart Association, are a “disorder of the heart’s electrical system, like other arrhythmias.”

“LQTS can cause abnormal heart rhythms in response to exercise or stress,” the Heart Association says.

To manage her condition, the lawsuit posted online on Fox News says Katz abstained from energy drinks and highly caffeinated beverages and would drink “electrolyte drinks, like Gatorade.”

“She was very, very vigilant about what she needed to do to keep herself safe,” her roommate and close friend, Victoria Rose Conroy, told NBC.

On Sept. 10, 2022, Katz bought a charged lemonade from a Philadelphia Panera and went into cardiac arrest hours later. She was taken to the hospital and went into cardiac arrest a second time, which is when she died.

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A large Charged Lemonade at Panera, which Katz bought, can have 390 milligrams of caffeine — more than any size of the company’s dark roast coffees, per the complaint. Panera’s website says guarana extract, commonly used in energy drinks, is one of the lemonade’s ingredients, as well. The FDA guidelines state a healthy adult should have no more than 400 milligrams of caffeine a day.

“I guarantee if Sarah had known how much caffeine this was, she never would have touched it with a 10-foot pole,” Conroy said.

However, the lawsuit states the charged lemonades were listed “side-by-side” with all of Panera’s non, or less-caffeinated, drinks.

“It was not advertised as an ‘energy drink,’ at the store,” the lawsuit states, including photos of the display to back up this claim.

The lawsuit drew a comparison between the charged lemonades and the Gatorade beverages Katz liked. Though they contain no caffeine, the drink uses a “charged symbol” to represent hydration.

“I think everyone thinks lemonade is safe. And really, this isn’t lemonade at all. It’s an energy drink that has lemon flavor,” Elizabeth Crawford, a partner at the Philadelphia-based law firm Kline & Specter, PC who is representing the family, said to NBC.

Crawford shared a medical examiner’s report with NBC, showing Katz’s cause of death was cardiac arrhythmia due to long QT syndrome. The examiner’s report notes Katz had no drugs in her system, other than those used by the hospital to save her.

Panera’s charged lemonade has made news before. A couple months after Katz died, a TikTok user made a viral video, in which she said she says she drank multiple cups of the beverage without realizing it was caffeinated — and was thusly surprised at the amount of energy she had. The video, posted in December 2022, was captioned: “This drink should come with a warning because it’s delicious and will lead to my cardiac arrest.”