Green’s Dictionary of Slang

an onomat. term indicating an explosion.

1971		L. Bangs in Psychotic Reactions (1988) 11: This time the guitars will jell like TNT and set off galvanic sizzles in your brain ‘kablooie!!!’.
2001		(con. 1964–8) J. Ellroy Cold Six Thousand 396: A man said, ‘A nigger church just went ka-blooey.’.