Three Days Grace has announced that lead singer Adam Gontier has left the group because of a health issue.

The news was posted on their website, here: http://www.threedaysgrace.com/news/120901

As the news update says, the band has a new lead singer already...a voice you might know...My Darkest Days lead singer Matt Walst. 

Maybe this has something to do with the news from the weekend of Sal Costa leaving My Darkest Days...