A psychedelic celebration in San Francisco took a dark turn over the weekend when police discovered a trailer packed with nitrous oxide tanks just steps away from a concert series honoring the Grateful Dead’s 60th anniversary.
San Francisco police say the bust happened late Saturday night around 11 p.m. while officers were patrolling near Fulton Street and 35th Avenue, right outside Golden Gate Park—where thousands had gathered for the iconic band’s milestone event.
That’s when they spotted something suspicious: an “illuminated open trailer” parked near the festivities, with a man sitting inside. As they got closer, officers noticed the trailer was filled with large metal tanks—and quickly suspected they were loaded with nitrous oxide.
The man inside, identified as 32-year-old Thomas Siderio from Philadelphia, was taken into custody. Officers say they seized roughly 100 tanks along with numerous balloons, which they believe were intended for recreational inhalation of the gas—commonly known as laughing gas.
Siderio was booked into the San Francisco County Jail on suspicion of possessing and distributing nitrous oxide for intoxication purposes, a violation under California law.
Though nitrous oxide is legal when used in medical settings or as a food additive (like in whipped cream canisters), it’s illegal to possess or sell it for recreational use. Overuse can lead to serious health risks, including oxygen deprivation, nerve damage, and even death.
According to the San Francisco Chronicle, the gas is popular at music festivals and concerts for its euphoric, dizzying effects—but police say that doesn’t make it safe.
“Our officers will continue to patrol all areas of Golden Gate Park and the surrounding neighborhood,” SFPD said in a statement. “We’re dedicated to keeping everyone safe and ensuring concertgoers have a safe time while in our city.”
The weekend’s Grateful Dead celebration was supposed to be a major boost for San Francisco, with fans from around the country flooding into the city for music, food, and community. Local businesses reportedly saw a bump in foot traffic, and city leaders had praised the concert series for its economic impact.
“When we make space for creativity and celebration, the whole city benefits,” Mayor Daniel Lurie said ahead of the event.
Unfortunately, not everyone came just for the music.
Nothing to laugh about!