So mosques, which are not owned by any person in particular (and, similarly, schools, public works, properties, and general deeds of benefit to people) do not lie within Zakat's divinely delimited bounds.
Hazrat Usman (R.A), the third caliph of Islam was martyred at the age of 82 while Hazrat Ali (R.A), the fourth caliph of Islam was martyred at the age of 60.