Flooding is the deadliest natural disaster facing Oklahomans, a threat far greater than tornadoes. In the United States, flooding kills an average of 103 people a year. Tornadoes, however, caused 48 deaths on average during the same period, according to the National Weather Service.

The uncertainty about what happened at Mystic comes as local officials have repeatedly dodged questions about who was monitoring the weather and what measures were taken ahead of the flooding.