Tragedy struck the centuries-old Notre-Dame Cathedral in Paris, France yesterday when a nine-hour blaze devastated the iconic building. In mourning, people flocked to the building to serenade it; they shared their thoughts, feelings, and pictures on social media; and gamers booted up 2014’s Assassin’s Creed Unity to explore publisher Ubisoft’s gorgeous digital recreation of the building.

In Ubisoft’s long-running Assassin’s Creed franchise, players take the role of an assassin in a painstakingly detailed historical setting—the franchise’s hallmark. Previous games have featured Renaissance Florence, Cleopatra's Egypt, and 19th century London. In 2014, Ubisoft took the series to revolutionary France in Assassin’s Creed Unity, making the famed Notre-Dame Cathedral an important set piece.

In the wake of the destructive fire, which consumed the spire and police say began as an accident, gamers are returning to Unity to explore the cathedral.

“One of the most remarkable monuments we have ever had the grace of parkouring in is currently on fire,” redditor ‘Rick_The_Mullet_Man’ posted on the Assassin’s Creed subreddit on Monday. “I'm booting my AC Unity right now to see this beauty. :(“

The thread has almost two thousand upvotes and 213 comments, most sharing condolences and experiences with the cathedral and the game. “I think notre dame is one of the reasons Unity is my 2nd favorite game in the series (despite its flaws),” poster “arex333” said, “there is simply nothing like it in another AC game.”

“Dude I bought a copy of Unity today,” Redditor “Carseat_Brown” added. “I’ve been meaning to get around to it but once I heard about this, I couldn’t put it off any longer. It’s so tragic :(“

Assassin’s Creed is one of the biggest franchises in gaming and Ubisoft spends a lot of time and money to produce loving recreations of is historical settings. For Unity, level artist Caroline Miousse spent two years on Notre-Dame alone. “I made other stuff in the game, but 80 percent of my time was spent on Notre-Dame,” she told The Verge in 2014.

Notre-Dame dominates the middle of the map in Unity. It’s the game’s single largest structure and Miousse worked with a team of historians to get every little detail right—including the placement of paintings from the period. The only anachronistic feature is the inclusion of Notre-Dame’s spires, which weren’t yet constructed in 1789, which is when Unity is set.

Miousse visited Paris after finishing work on the game and marveled at Notre-Dame. According to The Verge, when the guards weren’t looking, she kissed one of its walls. "For me, it was a lot like visiting my home,” she said.

Update:

Ubisoft announced it would donate €500,000 to help with the restoration of Notre Dame.

“In addition, we want to give everyone the chance to experience the majesty and beauty of Notre-Dame the best way we know how,” Ubisoft said in a blog post. For one week, we will be giving Assassin's Creed Unity away free on PC, for anyone who wants to enjoy it. You can download it now for Uplay PC here: http://assassinscreed.com/unity-notredame/ or get it directly on the Ubisoft Store here: https://store.ubi.com/”

“It is important to keep in mind that what we did for the game was not a scientific reconstruction but rather an artistic vision,” Ubisoft told Motherboard in an email. “While we wanted to be very precise with details, there are some differences in terms of scale and with some elements. That being said, we would be more than happy to lend our expertise in any way that we can to help with these efforts.”