ATLANTA — It’s the drink that has gone viral. Panera’s caffeinated lemonade advertised as an instant energy boost – plant-based and clean – is now allegedly linked to a second death.

A new wrongful death lawsuit filed on Monday alleges Panera’s charged lemonades caused Dennis Brown to go into cardiac arrest after he left the restaurant.

“Dennis wanted to do well. He would let us know when he got the fruit instead of a cookie. There were times when we would go to eat, and he would get broccoli instead of French fries,” said Deann Burgess, Brown’s supportive life coach.

Those who knew and loved Dennis Brown were especially proud of his accomplishments that he conquered with challenges that came with having a chromosomal disorder.

According to the lawsuit, Brown had charged lemonades with his dinner at the Panera near his job in Florida and died while he was walking home. Receipts in the lawsuit show what Brown ordered and when it was ready for pickup.

Brown’s family said he avoided things like energy drinks because he had high blood pressure.

A large, charged lemonade has 390 milligrams of caffeine -- close to the FDA’s 400-milligram daily maximum intake.

It was first reported in October on the death of a 21-year-old college student who died after drinking the lemonade.

Sarah Katz, suffered from a heart condition and usually avoided caffeine. Friends and family said she likely didn’t realize the drink was caffeinated.

Her family also filed a lawsuit against Panera, arguing that the drinks were not properly labeled and were mis-advertised.

The restaurant chain is now including a warning label on its website, which reads:

“Naturally flavored, plant-based, with about as much CAFFEINE as our Dark Roast Coffee. Use in moderation. NOT RECOMMENDED FOR children, people sensitive to caffeine, pregnant or nursing women. Caffeine 260 mg.”

Panera released a statement about Monday’s lawsuit, saying:

“Panera expresses our deep sympathy for Mr. Brown’s family. Based on our investigation we believe his unfortunate passing was not caused by one of the company’s products. We view this lawsuit which was filed by the same law firm as a previous claim to be equally without merit. Panera stands firmly by the safety of our products.”

WSB-TV’s Michele Newell, WSB-TV and Gerald Wagschal contributed to this report.