A uranium hexafluoride leak killed two workers at the Philadelphia Naval Shipyard in 1944 when a weld ruptured on a cylinder containing the gas. The cylinder launched like a rocket, traveling 164 meters, tearing out pipes and equipment in its path, and exposing 20 workers to the gas.

In addition to the two killed, “three people were seriously injured, 12 were hospitalized for observation, and three were without symptoms,” according to the National Research Council report.

“The seriously injured individuals experienced chemical conjunctivitis with edema, chemical erosion of the cornea (resulting in temporary blindness), first-, second-, and third-degree chemical burns, nausea and vomiting, chemical bronchitis, pulmonary edema, and/or shock,” the report states. “The seriously injured workers completely recovered within 3 weeks of the accident.”

less than 50%

[link to www.forbes.com]