Put in grave situation — people in Northern Territory being detained (10)
I believe the answer is:
internment
'being detained' is the definition.
(being interned or imprisoned)
'put in grave situation people in northern territory' is the wordplay.
'put in grave situation' becomes 'inter' (bury in a grave).
'people' becomes 'men' (men are people).
'in' indicates putting letters inside.
'northern territory' becomes 'nt'.
'men' going into 'nt' is 'nment'.
'inter'+'nment'='INTERNMENT'
(Other definitions for internment that I've seen before include "Detention" , "Committal" , "Precautionary measure" , "Confinement of an enemy national" , "Locking up" .)