1999 Chicago earthquake

The 1999 Chicago earthquake was a 5.1 magnitude tremor that occurred at 1:20 PM EDT on March 3, 1999, killing seven people and causing minor damage to the city's power infrastructure, maintained by AEP.

History
The city of Chicago was completely unprepared for an earthquake even of this magnitude, unprecendented for the area. At precisely 1:20 PM EDT on March 3, 1999, a fault line that ran directly beneath the metro area, southwest of downtown, ruptured. Damage was mainly limited to burst fire hydrants and ruptured gas lines, but at least one gas station, located at the intersection of Jackson Street and North Dearborn Avenue, exploded, killing two. Other damage was limited to falling glass from windows and plaster from ceilings throughout the city, though five more were killed at street level by falling glass from the Aon and John Hancock Centers.

Aftereffects
AEP's power stations only suffered minor damage from the quake, but the real damage came when then-nine year-old Simon Lynch accidentally shut down the power grid at 6:12 that evening. Over the course of the next week or so, the USGS recorded ten aftershocks, ranging from 1.2 to 4.5 on the Richter scale.