Die Hard special effects were done by Boss Game Studios, who else was involved with the movie?
Boss Game Studios:  The company was formed as an independent offshoot of Boss Film Studios (a company that created special effects for feature films including "Die Hard" and "Ghostbusters"). Die Hard: Die Hard is a 1988 American action film directed by John McTiernan and written by Steven E. de Souza and Jeb Stuart.
John McTiernan