It’s a sad day in the world of pop music– Rich Cronin of the boyband LFO has passed away.

The pop star, who was most famous for the band’s hit “Summer Girls“, had been battling with leukemia for the past 5 years.

No official word from Rich’s camp yet, but his name is trending on Twitter and fans are already sharing their condolences on Rich’s Facebook page.

Lance Bass of the boyband ‘NSync (who was a close friend of Rich’s) tweeted about his departure:

“Sad sad day that Rich Cronin died- was a amazing guy. : (“

Rich celebrated his 35th birthday just a few days ago.

I had the pleasure of meeting him a few years ago and he was a really nice, humble guy. Sad to see him go.

R.I.P. Rich. You certainly left your mark in the music world.

Watch the “Summer Girls” video in Rich Cronin’s memory: