Underground ComEd transformer fire cuts power in Chicago's South Loop
May 2020Published 17 Sept 2026Responsible editor: Chief Editor
- Where
- near LaSalle Street and Harrison Street in the South Loop
- Operator
- ComEd
- What
- underground transformer fire in a manhole
- Injuries
- None reported
- Cause
- Under investigation
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Companies named in the reporting of this entry (being named is not a finding of fault): ComEd
What happened
On a Thursday in May 2020, Chicago firefighters responded to an underground electrical fire involving a ComEd transformer near LaSalle Street and Harrison Street in the South Loop. Southbound Metra traffic was stopped and several buildings lost power. The fire was reported out at about 6 p.m. ComEd said a fire in a manhole damaged equipment and cut power to 3,500 customers. About 3,000 had supply restored using generators, and the remaining 500 were expected to be restored that night by 11 p.m. No injuries were reported. The cause was under investigation.
Contributing factors
The cause was not reported. The utility said a fire in a manhole damaged equipment. An investigation was said to be under way.
Lessons learned
- An underground manhole fire can damage equipment and cut supply to thousands of customers even when contained quickly, so operators should review isolation plans for city centre plant.
- Temporary generators can restore most customers fast after an underground fire, yet a smaller group may stay off supply into the evening.
More lessons on electrical protection and isolation, outages, backup supply and restoration, from every incident on the register.
Not yet known
- Turbine or transformer model and age
- Total cost of damage and repairs
- Length of full supply restoration
This entry is updated when these are reported. Get an alert for the next one like it.
Source
Other entries that name ComEd
Other entries that name Loop
Published 2026-09-17. Written from public reporting. Descriptive, not investigative. See the data accuracy disclaimer.
