American transporter hit in Los Angeles (5)
I believe the answer is:
llama
'american transporter' is the definition.
(domesticated animal of the Americas)
'hit in los angeles' is the wordplay.
'hit' becomes 'lam' (to 'lam' means to hit hard).
'in' means one lot of letters goes inside another.
'los angeles' becomes 'la'.
'lam' placed into 'la' is 'LLAMA'.
(Other definitions for llama that I've seen before include "Peruvian beast of burden" , "S American animal like a camel with soft hair" , "one to chew the cud" , "mammal that chews cud" , "Domesticated South American beast" .)