Officials in Texas are facing mounting questions about whether they did enough to get people out of harm’s way before a flash flood swept down the Guadalupe River and killed more than 100 people, including at least 27 children and counselors at an all-girls Christian camp.

Social media users are spreading false claims that flash floods in Texas that killed more than 100 people over the Fourth of July holiday weekend were caused by weather modification.

In the early hours of July 4, the only sound many of the vacationers along the banks of the Guadalupe River would have heard was pounding rain and thunder. They didn’t get any official warning of the rapidly rising waters that ultimately proved deadly to dozens of people swept away in central Texas flash floods.

Central Texas, with its rocky soil, steep terrain and susceptibility to heavy rain, has been prone to devastating floods over the decades.