City getting disastrous coverage of display: topsy-turvy one, that is (7)
I believe the answer is:
pompeii
'city getting disastrous coverage' is the definition.
(Pompeii was covered by ash from Mount Vesuvius)
'display topsy-turvy one that is' is the wordplay.
'display' becomes 'pomp' (I've seen this before**).
'topsy turvy' shows that the letters should be reversed in order.
'one' becomes 'i' (Roman numeral).
'that is' becomes 'ie' ('i.e.' can be a synonym of 'that is').
'i'+'ie'='iie'
'iie' backwards is 'eii'.
'pomp'+'eii'='POMPEII'
'of' acts as a link.
(Other definitions for pompeii that I've seen before include "Ancient town near Naples buried by volcanic ash" , "Site of an Italian disaster of AD79" , "City destroyed but preserved by Vesuvius" , "Roman city south-east of Naples" , "Ancient Italian city" .)