For motorists in Los Angeles, getting stuck in traffic is part of daily life. The city’s sprawling road system is notorious for its rage-inducing gridlock, with one 2015 study finding that Los Angeles is home to 11 out of the 25 most congested segments of freeway across the country.

So when southbound traffic slowed to a halt Wednesday morning on the 110 Freeway during rush hour, it was just another day for commuting Angelenos. That is, until the source of the jam was revealed.

A shirtless man — later identified by police as Alexander Dunn, an aspiring rapper whose stage name is Dephree — had climbed to the top of a freeway exit sign wearing only black underwear and white sneakers, the Los Angeles Times reported.

Videos of the scene posted to social media showed Dunn shouting from a megaphone, dancing and rapping, only taking occasional breaks during which he vaped. On the sign, he hung banners, one of which had “Dephree” in graffiti-style lettering. Others displayed environmental slogans, including “Fight pollution, not each other” and “Give a hoot, don’t pollute.”

California Highway Patrol officer Dion Conley told the Times that calls about Dunn started coming in shortly after 8 a.m. Less than 30 minutes later, the Los Angeles Fire Department tweeted that a rescue effort was underway.

In addition to the fire department, highway patrol and the Los Angeles Police Department also arrived on the scene, according to NBC Los Angeles.

Times reporter Benjamin Oreskes took to Twitter to chronicle Dunn’s antics and the hours-long saga that ensued as police and firefighters attempted to get the rapper down safely.

By around 9:30 a.m., Dunn’s performance appeared to be nearing its end as authorities set up ladders and climbed the sign themselves in attempt to capture him. Below the sign, giant inflatable pads were set up, stretching across the freeway’s lanes.

But, Dunn proved to be a wily foe, managing to repeatedly outmaneuver law enforcement. At one point, after inching his way along the top of the sign and away from police, he raised his arms in victory.

Finally, authorities seemed to convince Dunn to get off the sign, but the rapper made sure to go out on his own terms. Surrounded by police, Dunn did a back flip off the sign, falling gracefully onto the inflatable pad as onlookers cheered raucously.

Upon landing, Dunn, who appeared to be uninjured, was arrested, the Associated Press reported. Around 10:30 a.m., roughly two hours after Dunn climbed the sign, California Highway Patrol tweeted that all lanes were open.

The feat was later revealed unsurprisingly to be a publicity stunt. Dunn’s producer King Graint told the Times that a music video, which would include footage of the rapper on the sign, was scheduled to be released Wednesday night.

According to NBC Los Angeles, Dunn was booked for delaying a peace officer, trespassing and failing to obey a regulatory sign.  He could also face additional charges if prosecutors determine that the stunt was done for commercial gain, the Times reported.