July 11 (UPI) -- One man is dead after fire inside a hyperbaric chamber in Lake Havasu City, Ariz. It's the second such fatality in the United States this year. The 43-year-old died after the "flash fire" earlier this week, officials confirmed in a statement on the city's website. The man was later identified as Walter Foxcroft, a physical therapist and founder of Havasu Health and Hyperbarics. The cause of the fire remains under investigation. Officials said it wasn't immediately clear why