-si-
It depends on alcohol sales. If a club wasn’t selling booze they could do 18+. That was VERY rare as how else is the place supposed to make money? I’m not entirely sure about Twilo but they might’ve had a grandfathered-in license; some places are allowed to operate outside of modern statutes if they’ve been around before the statutes were implemented. One the liquor license transfers hands, you have to adhere to current standards. But if you’re in continuous operation for like 100 years you’re good to go - no wheelchair ramps or 21+ requirements. It’s a precarious position to be in as you still can get sued in certain circumstances, just not by the government.
Now the places I was going as a kid back in 1997 were all warehouses. Not legal in any way. This one place in Oakland had the floor cave in. They used to do rooms on both floors. Lucky that night it was just the top floor so nobody was killed. And then there’s Ghost Ship a few years back. I was working at the bar that night. Crazy busy. Left around 4:00 AM and the smell in the air was just so odd. Found out the next day Ghost Ship and burned to the ground and 30 whatever people were killed, 2 of whom I somewhat knew. The underground dance music scene has never recovered and likely never will.
EDIT here’s a nice little track from one of the people who passed.