A single wall is all that’s still standing after a building collapsed in Elgin on Monday morning, a day after a vacant building in Chicago’s Englewood neighborhood met a similar fate. At least four buildings in three days have been felled by the weather, officials said.
And as storms continue pummeling northern Illinois, experts warn more old, vacant or poorly maintained buildings may buckle under the weight of the snow.
The buildings will likely be demolished, officials said — or at least, what’s left of them.
One’s already coming down. A vacant building in Englewood, at 5617 S. Halsted St., collapsed Sunday and was in the process of being demolished beginning the same day, according to the Chicago Fire Department, which works in cooperation with the city’s buildings commissioner, Matt Beaudet.
“When those buildings are unsafe, and there have been a few, we do take emergency measures and we do demolish those buildings on an emergency basis and we do place — the Law Department — will place a lien on the property so we can recoup our cost from the owner,” Beaudet explained during a news conference Monday.
The front and right walls of the commercial building in Elgin, in the 200 block of Prairie Street, are “gone,” taking out a graphic design studio and a banquet hall, according to Richard Carter, operations chief with the Elgin Fire Department.
Crews from the agency were on the scene five minutes after a 911 call about a possible explosion came in about 6:30 a.m. Carter said it’s not uncommon for people to mistake the noise of a building collapse for an explosion. No injuries were reported, he said.
In that instance, only the building’s rear wall remained, as its left wall is part of a neighboring building.
Another building’s roof fell through in Elgin on Saturday, Carter said, sending that structure tumbling down too.
Both buildings had bowstring truss roof systems, he said.
The style is common in older buildings with wide-open spaces, and is marked by an arched roof and, notably, a lack of support columns in the middle.
In Chicago, “we have responded to some roof collapses,” Beaudet said. “They are primarily the bow truss roofs, which are a lot older; those are about 100 years old in the city. A lot of those buildings are vacant.”
The roofs often fail in what Chicago Fire Department spokesperson Larry Langford called a “pancake collapse.”
“That’s where the roof just comes straight down,” he said. Other roof systems with supporting columns, in contrast, might come down in sections.
The Chicago Fire Department responded to the South Halsted Street call Sunday after that building caved in, shutting down traffic and prompting an emergency demolition.
Half a brick wall from another building in the Bridgeport neighborhood, at 2727 S. Wells St., fell into an alleyway Monday afternoon, in the city’s second building collapse in as many days.
The 94-year-old Aragon Ballroom also faced a partial collapse in early February, on a part of the building that the Fire Department said was damaged by a buildup of heavy snow.
The buildings were vacant, and there were no injuries when they collapsed, according to the Fire and Building departments. Both also had bowstring truss roofs, officials confirmed.
Why the trusses gave in isn’t yet known, said Mimi Simon, a Department of Buildings spokesperson.
But Beaudet said age, vacancy and the weight of the accumulated snow were main factors in the roof cave-ins. Many of those buildings, like the ones in Englewood and Bridgeport, were vacant and didn’t have heat, he said.
“The heat goes up, and the heat helps heat the building, heat the roof, and the snow will come down,” Beaudet said. “If you have an unoccupied building that’s been vacant, there’s no heat going up there; that’s where you can get the buildup a little bit more.”
Old buildings just might not be able to withstand the snow that’s rapidly accumulating, as back-to-back winter storms batter the Chicago area, officials suggested.
“The problem with some of these buildings is, as the snow falls and freezes, it can push against the edges of the roof, and that can cause some motion that will cause rafters to collapse or to fail,” Langford said. “In some buildings that are just large, open roof area, it’s just the sheer weight. On wood that’s 100 years old, it just goes.”
Jake Petr, a meteorologist with the National Weather Service, said as of Monday, Chicago’s official snow depth was 16 inches. That represents some melting, despite the bitter cold, as 28 inches of snow have fallen in the city in the past 19 days, according to John Tully, commissioner of the Department of Streets and Sanitation.
Not only has there been an unusually high amount of snowfall in recent weeks but, Petr said, the “character of the snow” makes a difference in its weight.
The season’s first big snowfall between Jan. 24 and Jan. 25 created a “base layer that is dense and heavy. And adding multiple layers of snow over time just led it to get heavier and heavier.”
Typically, it takes about 1 inch of moisture — water — in the atmosphere to create 10 inches of snow, he said. But for that first snow, the ratio was more like 1 inch of water creating only 5 or 6 inches of snow, which is even more remarkable considering the area got more than 6 inches from that system.
The more recent snow and the snow that was expected to fall by Tuesday morning is much lighter, and fluffier, snow, he said. It could turn 1 inch of water into 20 or 25 inches of snow. Lighter snow forms when the air is colder, like it has been this week, and warmer air creates more dense snow, which will be heavier on roofs.
“The temperature that the snow crystals form at play a big role in the type of snowflakes you’re getting, which then impacts the ratio,” Petr said. “It’s more characteristic of these arctic cold air masses to tend to favor fluffier, light snow. Where it’s transitioning between snow and rain when it’s warmer, you often get the heavy, wetter snow because the air above is a little bit warmer.”
A single cubic foot of snow can weigh as little as 5 pounds, or as much as 30 pounds, according to the National Roofing Contractors Association.
So how much snow is too much?
Maybe more than 10 inches, especially on older or poorly maintained buildings, said Salvador Pedroza, who founded and leads Economy Roofing in the Little Village neighborhood. For Pedroza, “The key word is maintenance.”
He recommended that building owners get their roofs inspected, re-roofed or replaced as needed, and, especially for owners of buildings more than 50 years old, get professional help for the snow and ice on their roofs.
That’s something that the city echoed after the Englewood building collapse: People should not try to shovel their roof.
“Don’t go on top of the roofs. That’s not the solution,” Beaudet warned.
“As building types, configurations and materials vary, (the department) advises building owners to monitor the impact of a large accumulation of snow and ice on their building structures, and contact a licensed professional to assess and evaluate any concerns related to the building,” the Department of Buildings said in a statement.
Are more collapses on the way?
Without a break from the snow and bitterly cold temperatures, Langford says yes.
“With this 10 inches we’re expecting now, we haven’t had much recovery since the other storms,” he said. “The temperature has not gone above freezing, so it’s all literally piling on. You can expect more of this.”
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