The two-hour special revolved around Maggie Pierce (Kelly McCreary) and the other doctors of Grey Sloan Memorial working to save the life of fire chief Lucas Ripley after he collapsed outside of a flower shop. Further tests later in the episode revealed Ripley's problems were much more severe, eventually leading to his heartbreaking passing.
After spending most of the episodes attempting to get in contact with his girlfriend Vic Hughes (Barrett Doss), Ripley leaves Grey Sloan against medical advice to try and find her. This happens just as Maggie finds out that the fire chief's condition is not related to an existing condition, but actually him getting poisoned with hydrofluoric acid during a fire response at a coffee beanery.
After he finds out the truth behind his condition, Ripley stops at Seattle Presbyterian hospital and Maggie attempts to treat him. Sadly, the damage to his body is too severe and by the time Vic arrives to see him, he is already at death's door.
The crossover ended on a tragic note, as Ripley accepted Vic's marriage proposal only for him to die seconds later.
Fans of both shows were left distraught by the tragic ending of the crossover event, sharing their sadness on social media.
"Currently ugly crying," one user said, quoting another fan who claimed to be victimized by the creator of Grey's Anatomy, Shonda Rhimes.
"Barrett Doss was incredible tonight [Station 19] her range of emotions: mad, scared, unable to move, & even her hand shaking right before she opens the door to see the love of her life one last time... we've all been there with a loved one. She made it real," Another fan commented, praising the actress' performance during the heavy hour.
"I haven't watched [Station 19] since last season, but here I am watching [Greys x Station 19] and crying hysterically! Thanks [Shonda Rhimes]," Anther viewer wrote.
The special episode added even more emotion by showing flashbacks of Vic and Ripley's relationship, including the first time they were confused for a married couple and when Vic met Ripley's sister.
Just before Ripley's collapse, the couple had been discussing how they could bring their relationship out of hiding at the station, with Vic suggesting they get married so their pairing was no longer inappropriate from a professional standpoint.
Ripley collapsed just as he was headed to his and Vic's favorite breakfast diner to say yes to her proposal.
"Not cool. Not cool at all. This broke my heart. One of my favorite characters," Another user wrote.
"Dear work, when I show up tomorrow with my eyes all puffy and swollen, don't blame me. Blame Shonda," Another fan tweeted.
Grey's Anatomy airs Thursdays at 8 p.m. ET, followed by Station 19 at 9 p.m. ET on ABC.