Have there been any SRB's not recovered apart from challenger?

I seem to remember something about pictures of a sinking SRB that didn't
have its chute deploy. If this is true did it float and eventually sink with
water entering? How quick where they there to take pictures and are these on
the net anywhere? Also why isn't the chute cut away just before water
landing? Seems like they get tangled and really form a mess for the divers.