Detective work on the Robbins bench

I've been trying to learn the back story on David R. Robbins, who is memorialized at this bench.

         

The plaque states that Mr. Robbins was born in 1959 and died young, in 1994.  But there is no listing for him in the Social Security Death Index.  I am perplexed.

Mr. Robbins was a son, a brother and a friend.  Unfortunately, his bench memorial seems to have come upon hard times.

 

It benefits from a gorgeous location, however.