Billie Eilish joins Green Day on stage at FireAid concerts

Billie Eilish made a surprise appearance on stage with Green Day on Thursday to kick off one of two star-studded concerts in Los Angeles put together to raise funds for people affected by deadly wildfires in California this month.

Eilish, who was scheduled to perform solo later in the night, joined Green Day for the rock band's song "Last Night on Earth" at an arena in Inglewood, California, for a benefit dubbed FireAid.

"It's one of the most important gigs we've ever played," Green Day lead singer Billie Joe Armstrong said in an interview before the show. He said the band had recorded several albums in Hollywood and regarded Los Angeles as a "second home."

"We've been coming here for 30 years, so it's just really important for us to sort of do our part in a small way," Armstrong said.

Other scheduled performers included Lady Gaga, Gracie Abrams, Katy Perry, Red Hot Chili Peppers, Sting and Stevie Nicks.

On screen, viewers were given a number to text or a website address to donate money to wildfire-related causes.

The funds will go to short-term relief and long-term efforts to prevent future fire disasters, organizers said. Money will be distributed with advice from the Annenberg Foundation.