Thinking anywhere open to the public is "safe" is just foolish.
Case in point: I was walking on a walking track with my girlfriend at a city park in a very popular relatively crime free tourist destination type of place in Appalachia (i.e. no projects or 'da' hood'). I see three teenage white thugs aproach in our direction on the track. One of them flings open a knife at ~30feet and makes direct eye contact with me/us. I quickly draw my S&W 442 and firmly say "you'll die" and he actually almost fell over and ran away. The other two dip****s were somewhat clueless to what just happened and one said "what thaaa,,...?" and I said while still in shooting stance "I'm a cop" and they ran off also.
You just never know when the fight comes looking for you. I couldn't have (or would not like to try) to fight off three teenagers with my fists.
This girlfriend also thought I was "paranoid" for carrying all the time even though I was a cop. She never thought that again after that day.