The blackout's proximate cause was a software bug in the alarm system at the control room of FirstEnergy, which rendered operators unaware of the need to redistribute load after overloaded transmission lines drooped into foliage.

[citation needed] A joint federal task force was formed by the governments of Canada and the U.S. to oversee the investigation and report directly to Ottawa and Washington.

On November 19, 2003, Abraham said his department would not seek to punish FirstEnergy Corp for its role in the blackout because current U.S. law does not require electric reliability standards.

"[11] In April 2004, the U.S.-Canada Power System Outage Task Force released their final report, placing the causes of the blackout into four groups:[12] The report states that a generating plant in Eastlake, Ohio, a suburb northeast of Cleveland, went offline amid high electrical demand, putting a strain on high-voltage power lines (located in Walton Hills, Ohio, a southeast suburb of Cleveland) which later went out of service when they came in contact with "overgrown trees".

The lack of alarms led operators to dismiss a call from American Electric Power about the tripping and reclosure of a 345 kV shared line in northeast Ohio.

[27] The following is the blackout's sequence of events on August 14, 2003[28][29][30] (times in EDT): *Ottawa-Gatineau is a special case in that it is divided by a provincial boundary and the Ontario and Quebec grids are not synchronously connected.

At Chicago's Midway International Airport, Southwest Airlines employees spent 48 hours dealing with the disorder caused by the blackout's sudden incidence.

Gas stations operating in pockets of Burlington, Ontario, that had power were reported to be charging prices up to $3.78 per US gallon (99.9 ¢/Litre) when the going rate prior to the blackout was lower than $2.65/gallon (70¢/L).

Those who relied on the Internet were similarly disconnected from their news source for the duration of the blackout, with the exception of dial-up access from laptop computers, which were widely reported to work until the batteries ran out of charge.

As a result, the internet editions of Advance newspapers as far removed from the blackout area as The Birmingham News, the New Orleans Times-Picayune, and The Oregonian were offline for days.

At one point a 7-hour wait developed for trucks crossing the Ambassador Bridge between Detroit and Windsor due to the lack of electronic border check systems.

Power was lost at the Oak Hill Country Club in nearby Pittsford, where the 2003 PGA Championship was being played, which caused minor interruptions to the tournament.

Major U.S. networks (CBS, NBC, ABC and Fox) and some cable television channels (HBO, MTV and Nickelodeon), centered in New York City, were unable to broadcast normally, so backup stations and flagship transmitters in Dallas were used for prime-time TV.

By late evening, the New York City Fire Department had reportedly confirmed that all stalled elevators in approximately 800 Manhattan high-rise office and apartment buildings had been cleared.

Mayor Michael Bloomberg advised residents to open their windows, drink plenty of liquids to avoid heat stroke, and not to forget their pets.

Since most perishable items were going to spoil anyway, many restaurants and citizens simply prepared what they could and served it to anyone who wanted it, leading to vast block parties in many New York City neighborhoods.

The Indigo Girls were scheduled to perform that evening at Central Park SummerStage, and the band took the stage as planned to play one of the only shows in the affected area, using generators that had been filled with fuel that morning.

[citation needed] The day following the blackout, August 15, the New Jersey Turnpike stopped collecting tolls until 9:00 a.m. Parts of New London, Hartford, New Haven, Litchfield, and Fairfield counties, from Greenwich to Danbury and Bridgeport were affected, although most of the state had power all evening, aside from a few momentary interruptions that caused computers to reboot.

A local controversy ensued in the days after the blackout, when the federal government ordered power companies to energize the HVDC Cross Sound Cable between New Haven and Long Island.

[38][39] A Marathon Oil refinery in Melvindale, near Detroit, suffered a small explosion from gas buildup, necessitating an evacuation within one mile (1.6 km) around the plant and the closure of Interstate 75.

News crews of the areas broadcast notices during their coverages of the blackouts to the Downriver residents, explaining why the pumps had shorted out, as well as to limit water usage.

West Michigan, including the communities of Grand Rapids, Muskegon, and Holland were mostly unaffected, although a large portion was within "seconds" of joining the blackout according to local U.S. Representative Fred Upton.

Communities affected in northern Ontario included Timmins, Cochrane, Sudbury, Kirkland Lake, North Bay, Wawa, and Sault Ste.

On the evening of August 14, Ontario premier Ernie Eves declared a state of emergency, instructing nonessential personnel not to go to work the next day and that rolling blackouts could occur for weeks.

[46][47] Many Torontonians remember that night as a moment where the community came together: "Without power, residents of Toronto took to the streets to help direct traffic; florists arranged flowers for weddings by candlelight; and convenience stores served customers in the blackness.

According to emergency officials in Erie, Crawford, Venango, Clarion, Bradford, Forest and Warren counties, outages lasted into the night, but there were no serious injuries or incidents.

Due to the regular announcements he gave in the days following the blackout, Eves enjoyed a moderate increase in the polls that his party took as a sign of an opportunity to call an election they could win, but they lost instead.

Half of the affected part of Ontario had power by the morning of August 15, though even in areas where it had come back online, some services were still disrupted or running at lower levels.

Preparations against the possible disruptions threatened by the Year 2000 problem have been credited for the installation of new electrical equipment and systems which allowed for a relatively rapid restoration of power in some areas.

[53] National news stations, such as the CBC and CNN, continued to cover the story by inviting politicians and electrical experts to discuss the situation and suggest ways to prevent blackouts.