Lab Worker Who Witnessed First Nuclear Chain Reaction Dies At 94

ORLAND PARK, IL -- The last known living witness to the world’s first sustained nuclear chain reaction at the University of Chicago has passed away. Theodore F. Petry Jr. died July 28 at age 94. Petry was a senior at Tilden Technical High School when he was recruited in 1942 to to work on the top-secret Manhattan Project. He was a long-time resident of Orland Park.

Born on the South Side of Chicago on June 21, 1924, Petry was two minutes older his twin brother, Arthur. While attending Tilden, a boys’ technical high school, Petry was a teenager when he was hired to work at the Met Lab led by Enrico Fermi, one of Italy’s top scientists who left when Mussolini assumed power, according to an interview Petry gave to the UChicago on the 75th anniversary of the historic experiment.

Scientists were in a race to produce a controlled nuclear chain reaction ahead of Nazi Germany for the purpose of creating the atomic bombs that were dropped on Japan and ended World War II. Petry started out as a gofer, fetching uranium and other radioactive material from downtown Chicago and carrying it back on the streetcar to Hyde Park tucked in his pocket. It was only when blood tests revealed that his red blood cell count had dropped, did the project give Petry a station wagon to bring back the radioactive materials in a lead box.

“At those times, jobs were jobs,” said Petry told UChicago in a 2017 interview. “But they didn’t say we were going to be building an atomic pile.”

As a laboratory assistant, Petry was one of 30 or so young men who helped build the 20-foot-tall reactor known as Chicago Pile-1 by stacking wood and cutting graphite blocks in an abandoned squash field beneath the football stadium on the University of Chicago campus. On Dec. 2, 1942, the world’s first controlled, sustained nuclear chain reaction was produced, ushering in the atomic age.

Shortly after the atom was split, Petry worked other manufacturing jobs for the war effort, sailing on an ore freighter in the Great Lakes and making engines for C-47 war planes, was a tool and dye maker for the Pullman plant. Eventually, he earned his teaching certificate and taught shop in the Chicago Public Schools until he retirement in 1982.

Upon the 20th anniversary of the first nuclear chain reaction, Petry joined a contingent of “CP1 boys” for a meeting in the White House Rose Garden with President John F. Kennedy.

Petry leaves his wife of 67 years, Adeline (nee Drews) and four children, Linda Jamison (Chris), Theodore III, Terrence (Ausra), Laura Dowling (Joe), nine grandchildren and six great-grandchildren. Visitation will take place Sunday, Sept. 2, from 1 to 4:30 p.m. with a celebration of life planned for 2 p.m. at Lawn Funeral Home, 7732 W. 159th St., Orland Park.

Ted Petry reflects on witnessing the world's first nuclear chain reaction at the University of Chicago in 1942 as part of the top-secret Manhattan Project.

~ Image via YouTube