Earlier this week, there was as a massive fire at an abandoned warehouse at 3757 S. Ashland Ave. in Bridgeport.

It was five-alarm (the worst in seven years), the building’s now being demolished, even though it’s still smoldering, and still looks like an ice palace.

But it begs an even bigger question: how many abandoned industrial buildings are out there?

The short answer: no one knows. But it’s not as simple as that.

The City of Chicago requires owners of buildings that are vacant more than 30 days to register with the city. It’s supposed to be updated every six months, and there are fines for not complying.

In the case of the Bridgeport warehouse, reports have now surfaced its owner is actually in jail for attempting to bribe an alderman. There were also numerous violations, including a previous fire, at that location.

The city says it doesn’t have a list or know precisely how many vacant commercial properties are out there, but there is at least one clue that we can get from parsing 311 complaints about vacant properties.

Between 2010 and this morning, there were more than 35,000 calls from people who specifically filed complaints about vacant properties.

Here’s a great map that parses that data by neighborhood. Those calls translated to about 24,000 properties.

You can file your own complaint about vacant properties here. You can look up individual properties, and see if they’re registered and have had other complaints, here.

Shawn Allee contributed to this report.