Comedian and actor Billy Crystal also shared a moving story about the loss of the home he's lived in with his family for 46 years, and the power of laughter was a method of perseverance. Green Day opened up the benefit concert and were quickly joined by Eilish for a performance of the band's "Last Night on Earth" from their 2009 album "21st Century Breakdown.

The first of two concerts collectively being referred to as FireAid kicked off at the Kia Forum in the Los Angeles city of Inglewood, to support relief efforts in the wake of the deadly wildfires that ignited earlier this month in the LA area, claiming 29 lives and causing billions of dollars in damage.

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.