Bat Guano Mining During The Civil War:
https://tshaonline.org/handbook/online/articles/dkc09

I have never heard of this place or such a thing happening over by Johnson City or Round Mt. or Willow City.

Blowout, Texas
More on primitive bat dooky mining and the hazards associated.
http://www.texasescapes.com/MichaelBarr/Blowout.htm

Blowout Community, a settlement fifteen miles northwest of Johnson City in northwestern Blanco County, dates back to 1854. That year a party of two dozen homesteaders from Kentucky settled on the east side of Comanche Creek near Comanche Spring, about three miles below the creek’s origin. As more settlers moved into the area the small community of Blowout developed upstream from the spring. The name came from Blowout Cave, located in a hillside east of Comanche Creek about a mile above Comanche Spring. The cave was at one time home to thousands of bats, and a great deposit of guano accumulated in it. Supposedly, ammonia and other gases from the decomposing guano built up in the cave, and when lightning struck at the cave mouth the gases exploded–hence the name Blowout. Today there is little trace left of Blowout Community or the settlement at Comanche Spring. Only isolated ranchhouses remain at those sites, and only scattered ranches can now be found among the rocky hills along Comanche Creek.