George Polgar, who founded a pediatric hospital in Nazi-occupied Budapest where he helped Hungarian Jews escape the death camp trains, led his family on a daring escape from Hungary following the failed revolution to overthrow the Soviet-controlled government, and later became a leading researcher in pediatric pulmonary physiology at the Children's Hospital of Philadelphia, died April 17 in Havertown. He was 96.

He died of natural causes at the Quadrangle Senior Living Community, where he had lived for 20 years, said his son, George Polgar Jr.

"To me he was always a heroic figure," said his son.  "He did epic things because he grew up in an a place and time when you had to do epic things just to survive."

Among his many accomplishments, Dr. Polgar was one of a team of three doctors at Penn who developed technology that has saved the lives of countless premature infants over the last 40 years.

Dr. Polgar often told his family that he had decided to become a doctor when he was 5 years old. Born in Gyongos, György Polgar earned his medical degree at the University of Szeged in 1938.

During World War II, his family was persecuted by the German-aligned Hungarian government and stripped of its vast vineyards, a large wine-making operation and businesses that included a bank and law firm, said George Polgar Jr. Despite the setbacks, and under constant threat of imprisonment and deportation to the concentration camps, Dr. Polgar continued to treat patients.

He opened a children's hospital in the Budapest ghetto in 1944. Jews had been largely protected by the government until then. But after the Hungarian government began armistice negotiations with the Allies, the Nazis invaded and occupied the country and 400,000 Hungarian Jews were killed or deported to the concentration camps in the last year of the war.

Like his contemporary Raoul Wallenberg, Dr. Polgar used everything in his power to save as many people as possible. Among those he tried to save were his own parents.

"My father got his own parents off the death trains at least once," said his son. "He couldn't do it a second time. They were sent to Auschwitz."

Hungary was liberated by the Soviet Red Army in 1945 and Dr. Polgar was briefly imprisoned. After his release, he rose to a senior post at the leading pediatric hospital in Budapest without joining the ruling Communist Party, said his son.

The Hungarian Uprising erupted in 1956 to overthrow the Communist regime. The Soviets invaded Hungary and swiftly crushed the revolution. As the Russians began to secure the borders and lower the Iron Curtain, Dr. Polgar decided it was time to flee.

He enlisted the help of revolutionaries who guided the Polgar family -- his wife Katalin and his three children ages 2, 9, and 11 -- in a nighttime trek into Austria.

"The guys who led us out, the Hungarian freedom fighters, were shot and killed on their way back," said George Polgar Jr. "We heard the gunshots after crossing the border."

The Polgars emigrated to the United States in 1957 and settled near Philadelphia. Dr. Polgar rose to the position of associate professor of pulmonary physiology at the University of Pennsylvania and served as a physician at Children's Hospital.

He also served as head of the Pulmonary Pediatrics Department at Wayne State Unviersity and Children's Hospital of Detroit and was a visiting professor of medicine at the University Hospital of Geneva. During his tenure in Switzerland, he treated Sophia Loren's children and members of the royal family of Saudi Arabia.

Dr. Polgar was an aficionado of classical music and was an accomplished pianist. He was also an avid world traveler and photographer. He enjoyed reading literature in his native Hungarian, English and German.

He is survived by children Barbara Massey, Steven and George Polgar, three grandchildren and two great grandchildren. A memorial is scheduled for Sunday, April 26 at 1 p.m. at the Quadrangle Senior Living Community in Havertown.

Donations may be made to the Cystic Fibrosis Foundation.

Contact Sam Wood at 215-854-2796 or samwood@phillynews.com. Follow @samwoodiii on Twitter.