As a former raver, best nights of my life, the only time I felt like I was in a "deathtrap" was in actual licensed nighclubs that were supposed to follow all the "rules"; overpacked sardine can type affairs.

The "illegal" ones were usually outdoors, or in massive spaces where exits were easy to find.

Other than that tragedy in Oakland, which has been pointed out, was more of a flophouse with extension cord wiring everywhere, I think most "nightlife tragedies" came from actual bars and nightclubs, with pyrotechniques being involved.