The circumstances surrounding the closure of Onassis Coney Island in Detroit’s Corktown neighborhood at a key intersection remain a mystery.

Even the restaurant’s landlord had no idea it shuttered when I talked to him Tuesday morning.

Of course, restaurants in general have been battered by the COVID-19 pandemic and government shutdowns of indoor dining as part of broader efforts to slow the spread of the virus that has claimed more than 15,000 lives and infected 575,000-plus.

The neighborhood has also seen a wave of residential and hotel development plans, along with, of course, Ford Motor Co.’s underway redevelopment of the Michigan Central Station building as part of a $740 million autonomous and electric vehicle campus.

As Bridge Detroit’s Louis Aguilar first noted on Twitter Friday, we don’t know whether one of those factors or something else entirely was the main impetus for the closure.

But regardless, it has certainly sparked speculation.

In quick succession on Saturday morning, my cell phone got the same unverified rumor twice within the span of literally five minutes regarding what will next occupy the space.

I sent direct messages (DMs, as the kids say) to the Onassis Instagram and Facebook accounts seeking additional information today but have not heard back.

“Our time serving you on the corner of Michigan and Trumbull has come to an end,” a note on the door says. “Corktown has been good to us and will always hold a special place in our hearts. We have been in the restaurant business for a long time, no location will ever compare to our customers here. We will miss you and can’t thank you enough for all the love, support and appreciation we have received over the last 10 years. We will keep you posted on our social media pages (IG/Facebook) on where our next venture will be, if lucky not too far.”

The 2,000-square-foot building is owned by Joe Mifsud, but he told me a few hours ago that he was not aware of the closure.

He abruptly hung up the phone Tuesday morning, saying he had to get down to Detroit.