Crews have been spotted installing plexiglass windows at Lee Plaza.

That’s the 15-story Art Deco former luxury apartment building on West Grand Boulevard that dates to 1927. The news comes from the Historical Detroit Area Architecture Facebook group.

It’s not immediately clear who is doing the work, or why. Earlier this year, three groups submitted proposals to the city to redevelop the building for mixed-income residential and ground-floor commercial. Rod Liggons, the director of community affairs for the Detroit Land Bank Authority, says the building is still owned by the city, not the Land Bank. Daily Detroit reached out to the city and will follow this story if and when we get new information.

According to the website Historic Detroit, the Lee opened in 1927 as the tallest building on West Grand Boulevard and closed in 1997. It was added to the National Register of Historic Place in 1981.

Over the years, the building has been a poster child for the problems of metal scrapping and vandalism in Detroit. And around the turn of the century, more than 50 terra cotta lion heads that adorned the building were stolen, some of them later turning up at a high-end condo development in Chicago.

Most famously, the building saw its copper roof stripped in 2005.

Daily Detroit’s Shianne Nocerini toured the building last year and talks about what it was like inside in the segment, which you can listen to above. We also discuss some of the challenges that will come with redeveloping Lee Plaza.