"Grey's Anatomy" will air a record-breaking episode Thursday night, cementing the show as the longest-running primetime medical drama in TV history.
To mark the momentous milestone, "Good Morning America" reflected on how the doctors of Grey Sloan Memorial Hospital have broken barriers for women, minorities and more in Hollywood since the series debuted 15 years ago.
When the show premiered in 2005, it generated buzz for its diverse characters, something cast members say they take pride in and credit executive producer Shonda Rhimes for.
"She absolutely changed the game," said Ellen Pompeo, who plays Meredith Grey. "I don't care what anybody says. She changed the game."
(MORE: 'Grey's Anatomy' stars share their all-time favorite episodes and more behind-the-scenes secrets)Kelly McCreary, who plays Dr. Maggie Pierce, said she remembers "being kind of gobsmacked by it when I first came on."
"I thought, like, 'Wait, so, the Asian lady and the black dude and the other black dude ... they're all like kind of equals in this world,'" she added.
Chandra Wilson, who portrays Miranda Bailey, said she thought there was no way she would get the part when she first auditioned, as it originally called for a blonde actress.
"It wasn't for me at all," she said. "They were looking for a short, white, blonde female that they call 'The Nazi.'"
(MORE: 'Grey's Anatomy' cast reflect on the show's most iconic love stories)Debbie Allen, who both produces and stars in the show, said it's all about empowering other women.
"It is a friendly place for women's empowerment because finally, you have all of these women who are sitting in places of power who are in charge," Allen said.
"So we are reaching out to one another," she added. "We're not leaving people behind. We are bringing in more."
James Pickens Jr. said being a man surrounded by so many strong women is "a lotta fun."
"I think every man would like to do that, have such strong women around them," he added. "It keeps you vibrant and it keeps you on your toes. And they're amazing actresses, all of them."
One of the hardest parts of becoming so invested in the show for many fans is having to say goodbye to so many beloved characters who come and go -- often in dramatic fashions.
Justin Chambers, who plays Dr. Alex Karev, said he credits this in part to the success of the show. Seeing how invested the audience is in the characters has "been awe-inspiring just to witness."
"I would bring all of them back for a second," he added of the beloved, departed characters. "They're a big part of our success."
Pompeo, whose character has survived devastating loss and heartache, reflected back on the biggest moments for Meredith Grey.
(MORE: Sandra Oh makes history as 1st Asian actress to host Golden Globes, then wins award later in night)"Well, obviously, the loss of Sandra Oh was one of the most devastating for me personally," she said. "And she always knew that she only wanted to do 10 seasons."
"You have to respect that ... and let her go and not, you know, make her feel guilty," she said. "Like, 'Don't leave me,' or any of that, that you kind of want to do, but you can't."
Despite premiering 15 years ago, millions of new fans continue to discover the show every day thanks to streaming services like Netflix.
"I think that ... part of the reason why this show has lasted so long is because of social media," Pompeo said. "We've never seen this happen to a nighttime drama before."
(MORE: 'Grey's Anatomy' star Ellen Pompeo's secrets to success: Be a problem solver)"We've really never had a show that people can binge on Netflix and still watch live every week," she added. "So I think a tremendous amount of our success is due to streaming and social media."
Kim Raver, who plays Teddy Altman, said she is "grateful" to see a whole new generation just starting to get into the show now.
"I look at sort of my kids' generation and how there's this whole other, you know, group that's getting to watch the show," Raver said. "You're so grateful to be a part of that, and a part of that in that little blip of time in history."
100: How many hookups have taken place.
20: How many weddings have happened.
40: How many births.
50: How many dancing-it-outs.
20: How many punches thrown.
Four: The number of original cast members still on the show, 15 seasons and counting.
40+: How many doctors have scrubbed in since season 1.
29: The number of female directors who have stepped behind the camera for the show.
16: The number of major stars who've left fans shattered by their departure from Grey Sloan Memorial Hospital.
Millions: The number of new fans that discover "Grey's" each month through Netflix.
332: The number of episodes, including Thursday night's milestone.
