50 miles is on in earthquake design terms.
Most of the western United States is within 50 miles of a fault line.
In “design terms” being on the fault is not the same as being 50 miles away. Being on a fault line means the basic foundation of the structure is likely compromised during an earthquake. Not so 50 miles away. Earthquakes are attenuated the further you get from the epicenter. I suggest you go experience an earthquake at its epicenter verses 50 miles away and get back to us.