National Weather Service assesses damage from Thursday's storms, with 13 tornadoes confirmed in Chicago area

The National Weather Service on Sunday surveyed damage caused by severe storms that brought tornado touchdowns to the Chicago area and other parts of northern Illinois last week. 

The teams focused on central Cook County and areas south of the Kankakee River. NWS said crews had wrapped for the day, and confirmed 17 tornadoes so far, with 13 in the Chicago area.

One of the sites on which the teams are set to focus is the southwest Chicago suburb of Bridgeview, where the roofs of buildings in an apartment complex were ripped off by the storms on Thursday night.

Piles of debris stretched almost into the street. Different angles showed parts of the roof of a building hitting people's balconies.

It is believed that a number of people were displaced.

CBS News Chicago talked with the National Weather Service team responsible for the surveys.

"One is to assess portions of southern Cook County and into the city of Chicago," said Jake Petr of the National Weather Service. "It'll be especially challenging there, because there were two days in a row where there was large footprint of straight-line wind damage across those areas, so determining any localized tornadoes embedded within that line will be quite challenging."

National Weather Service teams on Sunday will also assess suburbs such as Hickory Hills and Justice, as well as areas farther south into Indiana.

Officials said the damage assessment could take several days. 

As of Sunday, the National Weather Service has confirmed at least 11 tornado touchdowns on Thursday, June 11, including an EF-3 tornado in Kouts, Indiana, an EF-3 tornado in Streator, Illinois, an EF-2 tornado in Merrillville, Indiana, an EF-1 tornado in Bartlett, Illinois, an EF-1 tornado near Dwight, Illinois, an Ef-1 tornado in Wenona, Illinois, an EF-0 tornado in St. John, Indiana, An EF-0 tornado in Cedar Lake, Indiana, and an EF-0 tornado from near Schneider to near Hebron, Indiana, an EF-1 tornado near Boswell, Indiana, and an EF-1 tornado east of Ludlow, Illinois, with most of this tornado's path in Champaign County in the National Weather Service's Lincoln area, but it crossed over into Ford County before it ended.

It was confirmed on Sunday that a brief EF-0 tornado touched down in Naperville and western portions of Lisle during the storms. It was also confirmed that an EF-2 tornado from Hickory Hills to near Midway Airport, an EF-0 tornado from southwest of Gibson City to near Elliott in Ford County, an EF-1 tornado between Paxton and Loda in Ford and Iroquois counties, and at least two EF-0 tornadoes across a corridor from Watseka, IL to west of Rensselaer, Indiana, in Iroquois, Newton, and Jasper counties.

The Enhanced Fujita Scale classifies the strength of a tornado from EF-0, the weakest, to EF-5, the strongest.

This came after a round of intense storms that brought down trees on Wednesday night.

Still another round of storms pounded the area Saturday night into Sunday morning, likewise bringing down trees and causing flooding. Some streets in Bridgeview were still without power early Sunday morning, and lights were flashing at intersections due to what was believed to be damage from the Saturday night storms.

ComEd working to restore power to areas impacted by storms

Meanwhile, utility crews are still hard at work, restoring power to thousands of people after this week's storms led to widespread damage. ComEd has been working to restore power for days, making their way through the south suburbs with crews at every turn.

"Entire sections of the electric grid were impacted, affecting homes, businesses, and critical infrastructure," said Jeremy Smith, ComEd vice president of distribution operations.

Downed trees and powerlines stretched across parts of Justice and Hickory Hills along Roberts Avenue, with multiple intersections not working properly because of all the outages.

"In a number of locations, we essentially had to rebuild parts of the electrical grid from the ground up. That includes replacing broken poles, rebuilding damaged sections of the system, and clearing extensive tree damage before power can be safely restored," Smith said.

ComEd has mobilized more than 3,000 employees, including lineworkers, tree crews, and damage assessors, along with help from other utility partners to get things restored as quickly as possible.

"Crews remain fully engaged in the remaining hardest hit areas," Smith said.

They say outages from Wednesday, Thursday, and Saturday's storms impacted over 650,000 customers.

"More extensive than we typically see and in some ways exceeding the impact we saw from the 2020 derecho, damage stretched across our entire 11,500 square mile territory," Smith said.

ComEd says they are expecting to have power restored for most of their customers by p.m. Sunday.