What does the cryptic crossword clue "A train that's derailed in capital city (6)" mean?

The definition is "capital city". The wordplay uses an anagram. anagram of A + TRAIN = TIRANA; definition: "capital city" The answer is TIRANA.

A train that's derailed in capital city (6)

Daily Mail Cryptic #17248 | 21 Down | 2023-12-12 flower