A large fire broke out by the Hollywood Bowl as concertgoers were leaving the venue following a “Sound of Music” singalong on Sept. 17.

User videos on the social media app Citizen showed firefighters rushing to put out palm trees that had ignited into flames. LAFD also requested the California Highway Patrol shut down one lane of traffic.

The LAFD posted a notice on its Twitter page after the blaze was under control, writing: “That somewhat stubborn fire near the @HollywoodBowl, our 1,423rd emergency of the day, thankfully involves only vegetation.”

The cause of the fire is not immediately known.

A user who had been at the Saturday night concert wrote, “Leaving the Hollywood Bowl after Sing Along Sound of Music and a small cluster of palm trees was on fire. It burned quickly and was barely embers by the time people reached their cars in stacked parking. While this was happening, the exiting crowd sang Do Re Mi in the tunnel.”

Another user described what appeared to be a fire that came without warning, writing: “Fire outside the Hollywood Bowl right now as we are all leaving the Sound of Music sing along it came out of nowhere — it wasn’t burning as we were walking out that literally just combusted.”

The Bowl’s season is in full swing with Rock and Roll Hall of Fame nominees Duran Duran recently wrapping a three-night run.

Last week, John Williams teased a snippet of “Indiana Jones 5” during a concert held at the Bowl.