SFPD anticipates 15,000 people for 420, warns about fentanyl-laced cannabis

FILE - In this Friday, March 22, 2019 file photo, a participant takes a very smoky puff from a marijuana cigarette during at meet and greet at "Tommy Chong's Live, Love, and Smoke Tour hosted by GreenTours in the Woodland Hills section of Los Angeles. Los Angeles prosecutors are joining other California district attorneys to tap technology that could wipe out or reduce more than 50,000 old marijuana convictions. District Attorney Jackie Lacey announced Monday, April 1, 2019, that she is joining forces with a nonprofit organization that uses computer algorithms to identify eligible cases. San Francisco became the first city in the state to work with Code for America to expunge or reduce 8,000 convictions. (AP Photo/Richard Vogel, File) less FILE - In this Friday, March 22, 2019 file photo, a participant takes a very smoky puff from a marijuana cigarette during at meet and greet at "Tommy Chong's Live, Love, and Smoke Tour hosted by GreenTours in ... more Photo: Richard Vogel, STF / Associated Press Photo: Richard Vogel, STF / Associated Press Image 1 of / 29 Caption Close SFPD anticipates 15,000 people for 420, warns about fentanyl-laced cannabis 1 / 29 Back to Gallery

With cannabis enthusiasts' annual feast day, 420, happening in California this weekend, the San Francisco Police Department is advising locals to be cognizant of massive crowds at Golden Gate Park's Robin Williams Meadow.

The authorities anticipate seeing upwards of 15,000 people visit that portion of the park on Saturday as early as 10 a.m., when people historically begin arriving.

For the occasion, the SFPD have fenced off a large area in the Meadow before the big 4:20 p.m. "smoke out." Those who do take to the event will be prohibited from bringing in certain items, including barbecues, glass, tents, tables and amplified sound equipment.

RELATED: The Waldos, joint-blazing San Rafael originators of term '420,' tell their story

Public transit has been readjusted to account for the influx of people. For those who don't take to Haight Street later, Muni will line up buses on Kezar Drive to shuttle attendees downtown. Between 3 p.m. and 6 p.m., the SFPD details, Kezar Street will be closed to other vehicular traffic, though there is a chance it may reopen earlier if crowds subside.

Other streets in the Upper Haight — in the area outlined by Oak Street to the north, Masonic Avenue to the east, Frederick Street to the south and Stanyan Street/Golden Gate Park to the west — may also be closed to vehicles, depending on the size of crowds.

RELATED: San Francisco's 2018 420 fest draws thousands of weed enthusiasts

SFPD Captain Una Bailey also warns visitors to the park to only purchase cannabis from licensed dispensaries beforehand.

"Last year we had numerous attendees pass out form using marijuana laced with fentanyl," she said in a press release. "Fentanyl is one of the strongest opiate drugs on the market being 50 to 100 times stronger than morphine. A tiny bit too much can be fatal."

For more information, view the SFPD's 420 event newsletter.

Alyssa Pereira is an SFGATE staff writer. Email her at apereira@sfchronicle.com or find her on Twitter at @alyspereira.

