Others said that even though they had attended the event — which was scheduled to run from 9 p.m. to 4 a.m. with a slate of electronic dance music — they had little idea how many people remained inside the warehouse-turned-artist collective they had escaped. [...] they knew that had they been on the second floor of the “Ghost Ship” collective on 31st Avenue in the Fruitvale neighborhood, their chances of getting out would’ve been close to nonexistent.