Sad week - one of our friendly neighborhood cats is gone

We live in a neighborhood and a lot of cats come and go through our yard.  For the past 4 years or so a neighbors cat has been a constant visitor.  During the cold winter nights she would come over and sleep in the boxes with blankets and an outdoor pet heating pad.  She also would eat here too when she was not at her own place.  Actually all of our neighbors take care of all of the cats so that none ever go hungry or don't have a place to get out of the cold.  So for about the past 4 years she has been in our yard all the time.  Such a sweet little thing.  While she has been here there have been 3 other cats that also come over and hang out all the time.  About a couple weeks ago one of the cats passed on.  She was pretty old and heard she had some health problems.  One of our neighbors saw her fall over and my understanding is she wandered off and died (on our side of the property, in which the owner reached underneath and pulled her out).  That was such a sad day.  She would come and just lay around enjoying the sun, or haning out under the covered porch when it rained so she would stay dry.  Every time we did yard work she'd just laid there and watched us.  So was just very sad.  But since then the other cats that used to come over and hang out will not come in our back yard now.  Makes me wonder if they saw her dead, but it's like they are afraid to come into our back yard.  If we are out front they will walk up, but they don't stay long.  We do have other stray cats that come through that are hungry, but I just really miss that sweet little thing and the friends who used to hang out here.  Just wanted to write that down.  Don't know why I'm so sad.  The cats have homes, so they are not hungry and if they do come here they can get food, and all the strays have something to eat.  Guess I'm just missing that sweet little cat and the our visitors that used to hang out here.