Throngs of spectators packed Santa Monica Beach Thursday night for the first of eight shows in the city’s popular Twilight Concert Series. The free performances have become some of the most popular seasonal spectacles in the Los Angeles area, but police and fire officials tell the Santa Monica Daily Press that they’re also a serious safety hazard.

Brooks says that police and fire officials were not equipped to handle the enormous crowd that attended Thursday’s performance—possibly the most well-attended show since the concert series began in the 1980s.

The concert began at 7:00 p.m., and by 7:11, the Santa Monica Police Department was already instructing visitors to “avoid the pier due to overcrowding.” After the show, headliner Khalid tweeted out an estimate that 60,000 people had attended the concert.

SMPD Chief Jacqueline Seabrooks tells the Daily Press that number is close to official estimates, and that allowing a crowd of that size to gather around the pier is “irresponsible.”

As the concerts have grown in popularity, some city officials have become concerned about their viability. This year, to address rising costs, the number of concerts was trimmed from 10 to eight, while concert organizers sought to rely more on private security, rather than higher-paid police officers.

In 2014, city officials estimated that the most popular concerts were drawing up to 30,000 spectators and the council approved a series of measures aimed at reigning in crowd size and reducing illegal activities like drinking and smoking on the beach.

But two years later, City Manager Rick Cole indicated in a blog post that the extension of the Expo Line and the opening of the Colorado Esplanade had contributed to record crowds at the summer concerts.

According to the Daily Press, Brooks has requested assistance from the Department of Homeland Security to create a plan for security at the concerts. She says that after attending attending Thursday’s concert, DHS experts “were not happy with what they saw.”