Content warning: This story includes suicide and descriptions of child sexual abuse that may be distressing to some readers.

Glee was one of the biggest shows of its time.

This week, the surprise hit celebrates 15 years since it premiered, with the series about a high school Glee club running from 2009 to 2015.

At its core, it was a fun, light-hearted show. It tackled some tough topics – not always successfully – but it tried, and mostly it was a wholesome feel-good watch for those who enjoyed positivity and acapella versions of songs they were already sick of hearing on the radio.

But beyond its happy-go-lucky surface, behind the scenes atGleewere many very dark, very ugly controversies.

From on-set bullying claims, allegations of racism and a toxic workplace culture, to three cast members' deaths – it's been a lot.

Here's how the controversies unfolded, one by one.

A look back at the first season of Glee. Post continues below.

Gleewas reportedly not a great set to work on.

Naya Rivera, whose character was Santana Lopez, described theGleeset as like a "polygamist cult" in her 2016 memoir, saying the cast would "bed-hop" and had "the sex drive of bunnies".

The creator of the show Ryan Murphy said in 2021 that he regrets the way he handled things on set, saying he should have fostered a more professional working environment.

"There was a lot of infighting. There was a lot of people sleeping together and breaking up. It was good training for being a parent, I’ll tell you that much," he said.

"But I also made a big mistake. We were always together, so there was no delineation between who was the boss and who was the employee. And we were all so close that finally when something would happen, it would be so personal to me that I would literally hit the roof."

Since the show ended there have also been countless accusations of bullying by Lea Michele, who played Rachel Berry.

In Naya Rivera's 2016 bookSorry Not Sorry, she reflected on her rocky relationship with Michele.

"Lea and I were like two sides of the same battery... We are both strong-willed and competitive. As the show progressed, though, that friendship started to break down, especially as Santana moved from a background character to one with bigger plot lines and more screen time," she wrote.

"I think Rachel – erm, I mean Lea – didn't like sharing the spotlight. Soon, she started to ignore me, and eventually it got to the point where she didn't say a word to me for all of season six."

In 2012, Kate Hudson guest starred in a few episodes of the show. Afterwards, she allegedly complained about Michele's behaviour, calling her a "nightmare" on set.

Reflecting on the experience,Gleestar Heather Morris said many of her fellow cast members were "scared" to report Michele's "bullying" to higher executives. She now wishes she had spoken up.

"We absolutely could have stepped up and gone to the Fox execs and said how we felt about the situation, and nobody really did," Morris said on the Everything Iconic podcast. "I think many people were very scared. I know, genuinely, I didn't feel like it was my place. And I don't know why, because I was a cast member just like everybody else, and we all deserve to feel comfortable on a set."

Cory Monteith's death.

On July 13, 2013 Cory Monteith – who played lead character Finn Hudson – was found dead in a hotel room in Vancouver.

The 31-year-old, who was in a relationship with his co-star, Lea Michele, had served several stints in rehab since he was 19, and had reportedly struggled with substance abuse since his early teens.

Gleecreator Ryan Murphy said Monteith's stint in rehab in March and April 2013 came after an intervention by cast and crew on the Paramount lot in Los Angeles.

His death was ruled to be accidental, the result of a toxic combination of heroin and alcohol.

In 2014, Michele said about Monteith: "I only have happy memories of Cory. He was not his addiction – unfortunately, it won," she told Seventeen.

"But that wasn’t who he was. Cory made me feel like a queen every day. From the minute he said, 'I'm your boyfriend,' I loved every day, and I thank him for being the best boyfriend and making me feel so beautiful."

Just three months after Monteith's death, assistant director Jim Fuller passed away from suspected heart failure, leaving cast and crew devastated, before production assistant Nancy Motes was found dead in a hotel room in February 2014 from a drug overdose.

Fellow production assistant Cristina Lageman spoke at the time of Motes' death about the impact the tragedies had had on "theGleefamily", with colleagues posting on Facebook: "We've lost another one."

Fast forward another few months and star Becca Tobin, who played Kitty Wilde on the show, lost her "workaholic" boyfriend Matt Bendik to a heart attack.

In 2011, Dianna Agron, who played Quinn Fabray, allegedly checked into a Los Angeles hotel under a pseudonym after her partner, fellow actor Alex Pettyfer, allegedly threatened her during a phone call, a couple of weeks after she moved out of their home together.

Naya Rivera was then arrested and charged with a domestic battery misdemeanour in late November 2017, after "getting physical" and allegedly hitting her then-husband, Ryan Dorsey, in the head and face. The star was released on a $1,000 bond and the charges were eventually dropped at Dorsey's request.

Mark Salling's crimes and death.

In 2013, Mark Salling, who played Puck, was accused of sexual battery by his ex-girlfriend and settled with his accuser out of court.

Two years later, police raided his home following a tip-off from one of his exes. He was arrested for possession of more than 50,000 child sex abuse images, reportedly found on his laptop and flash drive and in 2016 he was charged with receiving and possessing child pornography.

On September 30, 2017, he pleaded guilty and was expected to serve four to seven years in jail, register as a sex offender and enter a treatment program, among other conditions at a March 2018 sentencing.

But on January 30, 2018, Salling was found dead by suicide in Los Angeles.

Naya Rivera's death.

In July 2020, Naya Rivera's body was found in a Southern California lake where the 33-year-old went missing.

"Based on the location where the body was found, physical characteristics of the body, the clothing found on the body and the physical condition of the body... we are confident the body we found was that of Naya Rivera," Ventura County Sheriff Bill Ayub told media.

There was no indication of foul play or suicide – it was a tragic accidental drowning.

Rivera was discovered missing after her four-year-old son, Josey Hollis Dorsey, was found asleep and adrift on a boat in Lake Piru. The mother-son duo had rented a pontoon boat at about 1pm. Josey was found three hours later alone, after another boater raised the alarm. Rivera's car was found in a carpark nearby with her handbag inside.

The son later told authorities what he remembered happening.

"He and Naya swam in the lake together," Ayub said at the media conference. "It was during that time that her son described being helped onto the boat by Naya... He told investigators he looked back and saw her disappear under the surface of the water."

Authorities believed "she mustered enough energy to get her son back on the boat, but not enough to save herself".

At the time of her death, there were many tributes from across the entertainment industry, including many formerGleecast members. Some also went to the site of her death to mourn.

The Lea Michele accusations.

In 2020, the world watched the harrowing murder of George Floyd. His death sparked a rally for change, with millions joining the Black Lives Matter movement.

Lea Michele, like many other celebrities, publicly tweeted her support.

Her formerGleeco-star Samantha Ware responded to the tweet in all caps, calling Michele out for how she treated Ware on set. And it only snowballed from there.

Her account was backed up by otherGleeactors, including Amber Riley – one of the main cast members, who played Mercedes – who posted a GIF of her sipping tea. Alex Newell, who appeared on four seasons of the show, also backed Ware.

OriginalGleecast member Heather Morris then sent out a tweet: "Let me be very clear, hate is a disease in America that we are trying to cure, so I would never wish for hate to be spread on anyone else. With that said, was she unpleasant to work with? Very much so; for Lea to treat others with the disrespect that she did for as long as she did, I believe she SHOULD be called out."

And the allegations of bullying and racism continued.

LMAO REMEMBER WHEN YOU MADE MY FIRST TELEVISON GIG A LIVING HELL?!?! CAUSE ILL NEVER FORGET. I BELIEVE YOU TOLD EVERYONE THAT IF TOU HAD THE OPPORTUNITY YOU WOULD “SHIT IN MY WIG!” AMONGST OTHER TRAUMATIC MICROAGRESSIONS THAT MADE ME QUESTION A CAREER IN HOLLYWOOD… https://t.co/RkcaMBmtDA

— SAMEYAAAAAA (@Sammie_Ware) June 2, 2020

pic.twitter.com/mgq6Vtcmgm

— Amber Patrice Riley (@MsAmberPRiley) June 2, 2020

https://t.co/80ohlWM4Yd pic.twitter.com/tcfQyhgiGP

— Alex Newell (@thealexnewell) June 2, 2020

Child we ain’t got not a damn thing to lie about 6 years later! pic.twitter.com/TPRlKQdGLf

— Alex Newell (@thealexnewell) June 2, 2020

Days later, Michele apologised on Instagram.

"One of the most important lessons of the last few weeks is that we need to take the time to listen and learn about other people’s perspectives and any role we have played or anything we can do to help address the injustices that they face," she wrote.

"The responses I received to what I posted [on Twitter in support of BLM] have made me focus specifically on how my own behaviour towards fellow cast members was perceived by them. Whether it was my privileged position and perspective that caused me to be perceived as insensitive or inappropriate at times or whether it was just my immaturity and me just being unnecessarily difficult, I apologise for my behaviour and for any pain which I have caused."

The apology