Fall in warehouse (6)
This clue is a double definition.
'fall' is the first definition.
(going down is a kind of falling)
'warehouse' is the second definition.
(I've seen this before)
'in' acts as a link.
(Other definitions for go down that I've seen before include "Be recorded" , "Sink" , "leave university" , "Fall" , "Warehouse" .)
(Other definitions for godown that I've seen before include "eastern warehouse" , "storage facility in India" , "Leave university" .)