The U.S. has ten times as many more than Canada, so any and all crimes and/or accidents will be ten times greater.
Unstable or irresponsible gunowners are not a reason to limit access to firearms from law abiding citizens. If that were the case then we need to do the same with automobiles.
Just like anything else,education is the answer. Educating people on the use and care for firearms is the answer.
Besides, if you feel firearms are a threat or danger no one will force you to have one.