[Photo by: Twitter | @BLongStPaul]

UPDATE: Aug. 3 at 6:37 p.m. ET: 

Although Twitter believed that the “I love you Noel” sign in the crowd is what caused the singer to storm offstage, Liam just shared a tweet saying it was instead that his voice was “fucked”:

ORIGINAL: Aug. 3 at 6:06 p.m. ET: 

Ah, Liam. The former Oasis singer—and British icon known for his unexpected (yet kind of expected) actions—just let down plenty of Lollapalooza fans after storming offstage after playing 20 minutes of his 60 minute set.

This tweet kind of sums it up:

See the footage of Liam Gallagher storming offstage below.

Read more: “F*ck Oasis”—Band feud reignites, member calls brother a “potato”

According to fan footage at the festival, Liam left midsong, and once his band finished the song, they walked offstage, too. See a video of what went down below. (And note that you'll hear plenty of fans booing.)

No one is certain about exactly why he left, but speculations say that the “I love you Noel” sign in the crowd is what upset the singer:

Of course, Lolla-goers were not happy being let down by Liam, and the Twitter world is fired up. See some of the responses below:

What are your thoughts on Liam's Lollapalooza stunt? Let us know in the comments below!