SoftSwitching Technologies executive David Trungale says one of their monitors near Lansing first detected a deep voltage sag two seconds after 4:09 Thursday afternoon.
Seconds later, monitors around began to detect frequency decay in power grids in Ohio, which spread to Ontario, Canada; New York; Vermont and Pennsylvania.
Nationally, investigators have said the power disruptions likely began in the Midwest, but they have yet to pinpoint the cause.
Trungale won't say where the Lansing monitor was located, citing customer privacy.
Utilities and industrial customers purchase the monitors to get real-time information on power fluctuations. The monitors transmit data through phone lines to SoftSwitching's online data base.
Softswitching then monitors the readings and then notifies customers of power fluctuations.
