Flooding in Johnstown, PA, in 1889 Was Disastrous and Deadly

Multiple Choice

Flooding in Johnstown, PA, in 1889 was disastrous and deadly because

A) the town was built on a floodplain
B) the flood wave traveled at velocities as high as 60 km/hr
C) 20-25 cm of rain fell over a 24 hour period
D) an upstream dam failed
E) all of the above