Two weeks ago, all seemed right in Corey Monteith's world. On June 28, Monteith, his co-star (and girlfriend) Lea Michele, and a handful of other “Glee” regulars posed for Season 5 promotional photos in Los Angeles.

"Having the best time at our #Glee cast #Season5 gallery shoot! I can't believe it's our 5th season! Times flies when you're having fun:)," Michele tweeted.

Monteith and the rest of the crew were were scheduled to start shooting new episodes in mid-August. Now the show is in crisis after Monteith was found dead in a Vancouver hotel on Saturday.

Monteith's cause of death has not been released, and FOX officials say it is too soon to tell how his death is going to be handled on the show. The first episode of "Glee's" new season is scheduled for September 11th.

Producers are scheduling meetings to discuss how to move forward with story lines and other issues without Monteith's character, Finn Hudson. Industry experts say the actor's death will have a profound impact on the FOX series and pose significant creative challenges.

“Not only has Monteith’s character Finn been part of the show’s most significant romantic relationship opposite Lea Michele’s Rachel, in the fourth season he appeared to be being long-term positioned to eventually assume the role of glee club coach and overall student mentor should Matthew Morrison’s Mr. Shue leave the series,” Hollywood entertainment and pop culture expert, Scott Huver, told FOX411’s Pop Tarts column. “He leaves a major hole in the heart of the show that will be challenging for the writers and producers to address. While the ‘Glee’ staff and especially series creator Ryan Murphy have never shied away from handling controversial, tragic or dark subject matter, translating Monteith’s loss into a ‘death of Finn’ storyline may simply prove to be too sad and all-consuming for the show, but glossing over his absence seems unrealistic. Whatever they decide, the writers will have to proceed very delicately lest dealing with the outcome overwhelm the show’s generally light, fun-loving tone.”

Crisis communications expert Glenn Selig of The Publicity Agency said using what actually happened to Monteith may be the best way to help mourning fans.

“They may decide to handle what happened honestly; his character may be portrayed as dying suddenly and shockingly. That may provide both the cast and the public to grieve,” he said. “Whatever producers decide to do they will need to tread carefully because Cory Monteith was so well liked and what happened is so incredibly tragic.”

This is not the first time a show has had to scramble following the death of a leading star. When comedian Freddie Prinze died from a self-inflicted gunshot during the third season of the sitcom “Chico and the Man" in 1977, the producers considered cancelling the series but ultimately forged ahead by stating that Prinze’s character was on vacation in Mexico to finish out the season.

“They attempted to introduce other foils for co-star Jack Albertson, eventually introducing a storyline that revealed, vaguely, that Prinze’s character has died, but ratings dwindled and the show was cancelled soon after,” Huver said. “And when comedian Phil Hartman was killed by his wife in a murder/suicide in 1998, ‘Newsradio’ wrote out his character Bill McNeal with a sudden heart attack at the beginning of the sitcom’s first season, with Hartman’s longtime friend and ‘Saturday Night Live’ co-star Jon Lovitz coming on as a new character out of respect and loyalty to his friend, allowing the show, which had been cancelled and then surprisingly revived just days prior to Hartman’s death, to close out its final season.”

Then there was the sudden death of John Ritter early in the second season of his sitcom “8 Simple Rules.” The show also had his character die unexpectedly, and filled the void with guest stars James Garner and David Spade, who became regulars. The show only lasted through a third season.

One of the most successful handlings of the loss of a lead actor followed the death of ‘Cheers’ actor Nicholas Colasanto, who died of a heart attack in 1985. “The show acknowledged the death of his beloved character Coach, and even transferred the photograph of Geronimo that hung in the actor’s dressing room to a permanent place on the barroom set,” Huver said. “The writers concocted a reversal of the Coach character in Woody Harrelson’s Woody Boyd – instead of a disarmingly befuddled older bartender; he was a charmingly naive and simple young man new to the big city. Woody clicked with audiences and became a popular and vital member of the show’s ensemble.”

Although ratings for “Glee” have been slipping recently, it has been a huge hit for FOX overall, so much so that it was just renewed for another two seasons.

"We are deeply saddened by this tragic news. Cory was an exceptional talent and an even more exceptional person,” representatives for “Glee” Executive Producers, 20th Century Fox Television and Fox Broadcasting Company said in an official statement. “He was a true joy to work with and we will all miss him tremendously. Our thoughts and prayers are with his family and loved ones."

In addition to his work on “Glee,” Monteith, 31, appeared on television shows such as “Supernatural” and “Smallville,” as well as alongside Selena Gomez in the 2011 movie “Monte Carlo.” He currently has two completed films in the post-production phase – the crime drama “McCanick” and a comedy drama about four people struggling with the aftermath of trauma entitled “All the Wrong Reasons.”

Reps for FOX, Ryan Murphy and Ryan Murphy Productions did not respond to a request for further comment.

Danielle Jones-Wesley contributed to this report.