It’s been just one day since news broke that Mark Salling died at age 35 from an apparent suicide — and his former Glee co-star Lea Michele is having a tough time coming to terms with the tragedy. A source exclusively tells Life & Style that the “Cannonball” songstress, 31, is devastated.

“Lea is having a really hard time with Mark’s death. Of course, they weren’t close in recent years. But while they were filming Glee, Lea considered Mark a brother,” says an insider, adding that Mark’s death is especially difficult for Lea since her former boyfriend and fellow Glee alum Cory Monteith passed away in 2013 at age 31 from a drug overdose. “It’s particularly heartbreaking for her after Cory’s death,” the source continues. “She can’t believe another person from the cast is gone.”

lea michele mark salling - getty

Lea and Mark filming Glee in NYC in 2011.

As previously reported, Mark’s body was found near a Los Angeles riverbed on Tuesday, Jan. 30. The actor — who played bad boy Noah “Puck” Puckerman on Glee — took his own life one month before his sentencing date for child pornography possession. He was arrested in October 2015 and agreed to a guilty plea deal with prosecutors two years later in October 2017. He was scheduled to appear in court for sentencing on March 7.

Mark had agreed to four to seven years in jail, in addition to registering as a sex offender after his prison stint concluded. As a registered sex offender, the Texas native would have been ordered to stay at least 100 feet away from schools, parks, public swimming pools, playgrounds, and video arcade venues.

Hours after Mark’s death made headlines, Jane Lynch — who played Glee’s gym coach Sue Sylvester — told TMZ that his passing was “sad and very tragic.” Despite his crimes against children, Jane, 57, remembers Mark as “the guy who made that really sweet video in the beginning of Glee when he was so happy to be a part of this group.” She added, “It’s tragic and I’m brokenhearted over it.”

If you or someone you know is contemplating suicide, call the National Suicide Prevention Lifeline at 1-800-273-8255.