The factory closed down in the late 1990s, as part of the nationwide reforms on State-owned enterprises. This was followed by his parents' divorce.

During the first days of 2017, Li took his wife to show her where he was raised, and learned that the building was soon due to be pulled down.

"It's like an old item or an aged person that's always guarding you. You assumed it would always be there, only to find it's dying," Li says. He felt like having to do something instead of just letting it go.

"When my grandma passed away, we held a solemn farewell ceremony at the funeral parlor just across from the theater. So I thought I could create something really artistic and architectural to bid farewell the venue."

Li then talked to his parents separately. The divorced couple had not seen each other for a decade, but both supported the project. His father, a graphic designer, offered to get involved in the installation work.

"There had been tension between me and my father. Probably he wanted to find a way out for us, so he suggested that we could just do something together, instead of talking about our emotions," Li says, adding that their relations improved after the project.

So the father and the son started the project. They soon found out, to their surprise, that an old acquaintance was still there. Clad in a security guard's uniform, the mentally-challenged middle-aged man, who when Li was a boy was known for saluting everyone he met as if he was a soldier, greeted them both with smart salute, just like the old days. They were delighted when he became part of the project, diligently guarding their materials during the night.

When the installation was completed, Li's parents uploaded a poster on their WeChat moments, inviting former colleagues to join the theater's 40th anniversary and its "last curtain call".

The former workers came in groups, watching slide shows, taking photos and dining together. Some were unable to hold their emotions in check.

Some also brought their children thereby ensuring that memories would be passed on.

Up until this project, Li had been unsure what direction his architecture should take.

In his 9-year career after graduating from the Central Academy of Fine Arts in Beijing, he has often been conflicted by various kinds of social relations with his clients, which to some extent would affect his designs.

But for him, the installation was like a firework the moment it explodes, releasing a huge burst of energy and engraving a memory in the minds of a whole group of people.

"If I am to be an architect for the rest of my life, I'd like to try my best to influence the small group of people that would profoundly relate to my works, just as I achieved with this installation," he says.

The demolition was canceled two days after the farewell, probably due to lack of funds, Li says, adding that he will go there again to record its last day.