Who is responsible for missing outside items

[Tim B.]

I have a rental property in NC that has a few storm drains in the yard. There are steel grates covering the drains for safety reasons. My tenant called the property manager today and said the grates are gone and need to be replaced. The grates were properly installed when the tenant moved in (August 2013) and had been there for about 10 years since the property was built. My question is: Who is responsible to replace these?

Thanks in advance for your responses.

Carolinatim