Dr. Donald Liu was in Michigan with his family when it happened.
Known for his bedside manner and brilliance, Dr. Liu was completely devoted to saving children, which is why his University of Chicago colleagues are not surprised Liu tried to save the lives of two kids while he was enjoying a weekend at the beach away from work.
"We know given the same set of circumstances he would have done it again," said Dr. Jeffrey Matthews. "He would do anything for children."
The 50-year-old highly-regarded pediatric surgeon at Comer's Children's Hospital tried to save two kids in rough waters off of lakeside Michigan.
The children made it back to shore safely, but Dr. Liu was caught in a riptide. Dr. Matthews of the University of Chicago's calls his friend a legend in the medical community and a hero.
"He would operate long into the day and well into the night next day he would day he would do whatever it took no matter how physically exhausted to save children," Dr. Matthews said.
Bailey Brower was just one of many sick children Dr. Liu saved. Born with multiple health problems, Brower as an infant was given a 10 percent chance to live. This month, Brower celebrates her 10th birthday, and her parents credit Dr. Liu.
"I don't know how to put into words somebody who has given you your daughter," said Scott Brower. "My wife and I are both in a state of shock right now that we have our daughter because of Dr. Liu and here's a family that's now suffering based on his desire to save more lives, it appears."
Dr. Liu joined University of Chicago 11 years ago. In 2007, he was made surgeon-in-chief at Comer Children's Hospital. Dr. Liu was in Michigan for the weekend with his family.
He is survived by his wife Dr. Dana Suskind. She is also a surgeon at Comer Children's Hospital. They have three children together, ages 13, 10 and 7.
Suskind told ABC News that the couple's children begged their father not to go into the water before he went in to save the two children, who were family friends. Suskind says she performed CPR on her husband but could not revive him.