This Maller Building had a fire back in 2018 that torched the entire 4th floor. This latest fire started on the 10th floor. It’s a building heavy with jewelers and, to be frank, nearly every commercial fire is suspected arson.
That’s not an accusation here, it’s just that the fire department and insurance companies have so much experience that they’re suspicious from the start. Plus, businesses have been under enormous economic pressure with all the Covid related lockdowns, etc.
One other odd thing is that fires have neighborhoods or buildings that they seem to like. It’s not unusual to find high fire blocks in neighborhoods or even individual buildings. So as rare as a fire is in general, they can sometimes eerily fit a pattern.
For certain there will be smoke damage to the surrounding units and even to adjacent buildings.
11/15/20 Update: It was arson. https://chicago.cbslocal.com/2020/11/15/daniel-nieves-23-charged-with-arson-after-police-say-he-admitted-to-setting-fire-at-mallers-building-on-jewelers-row/