The Lollapalooza Music Festival was suddenly canceled Thursday evening over weather concerns.
An estimated 400,000 festivalgoers were asked to evacuate from Chicago's Grant Park at around 9 p.m., per the event's Twitter account, while headliners including Lorde and Muse were still performing on stage.
Footage captured by attendees and shared to social media feature lead singer Matt Bellamy and Lorde addressing the crowds before exiting.
The Melodrama artist expressed her disappointment over the cancellation. "f--ks sake," Lorde tweeted. "i am so gutted guys i don't know what to tell you... they've told us we can't play. i had the most spectacular show planned for you and i PROMISE i will come back to play it as soon as i can."