Remarriage and survivor benefits

In the case of remarriage, your ability to get benefits based on your first spouse's record depends on WHEN you remarried.

Generally, you cannot get widow’s or widower’s benefits if you remarry before age 60. But remarriage after age 60 (or age 50 if you are disabled) will not prevent you from getting benefit payments based on your former spouse’s work. And at age 62 or older, you may get benefits based on your new spouse’s work, if those benefits would be higher.

http://www.ssa.gov/pubs/10084.html#3

Here is information regarding what to do when a beneficiary passes away :

http://www.ssa.gov/pubs/deathbenefits.htm