According to this vehicle safety rating site, the Prius C is pretty poor compared to other new cars, mostly because of vehicle size/weight:
"LEAST SAFE [NHTSA side impact rating in bottom 11%] [79% higher driver fatality risk than the average passenger vehicle—based on class/weight] ".
Enter the model information and see for yourself:
https://www.informedforlife.org/display_vehicle_score.php
They put a lot of emphasis on vehicle weight:
