An oxygen tank leak at the former Shawano Medical Center, 309 N. Bartlett St., caused an evacuation of nearby homes for about 40 minutes Sunday night.
A loud hissing sound and a huge cloud were reported just after 10 p.m. A second caller reported two tanks leaking gas.
Shawano police and the Shawano Area Fire Department responded to the scene. By 10:40, the scene was under control and people were allowed to return to their homes.
The cause of the leak was under investigation.


