As in Synonymous

Chest

like vault

or treasure keeper-

holder

as in Heart

or locket, like a lockbox

fitted with skeleton key-

hole-

simply very heavy

and something

sounds 

broken

inside.

Unable to lift alone

as pallbearer in the past

I feel the dead weight 

familiar remembering

without seeing

This must be why

we bury our dead

in wooden chests such

as these 

likewise.

Photo credit: Harris & Ewing, photographer, taken 1925 in Public domain, via Wikimedia Commons.