Evaluating Solution Effectiveness Practice Test

Tornadoes can destroy homes and hurt people. A community built 50 underground storm shelters made of concrete near homes. After 2 years and 5 tornadoes, all 50 shelters were undamaged; 347 people used them with 0 injuries or deaths, even when 23 homes above shelters were destroyed. Two people died because they did not reach a shelter in time. Based on the evidence, is the claim supported that underground shelters are effective at protecting people?

Before the retention pond, flood damage averaged $200,000 each year; after it, damage averaged $25,000, and the pond cost $150,000 to build. Using the data provided, which claim about the pond is supported?