If it had not been preceded by thenee-naw of fire engines it meant that no warning had been given. There would be casualties.
2004, Neil Humphreys,Notes from an Even Smaller Island:
Whenever an opponent went down, be it genuine or feigned, the West Ham faithful would simultaneously cry 'Nee-naw, nee-naw, nee-naw, nee-naw', mimicking the sound of an ambulance.
2007, Penelope Lively,Consequences:
Tom is in rapt communion with his police car, lying on his stomach, pushing it round and round, makingnee-naw noises.