nvestigators of North America's biggest blackout say all
signs from a nearly completed timeline point to human errors in the
early stages in Ohio on Aug. 14 as the cause of the cascade into
They have nearly finished assembling a second-by-second
chronology composed of millions of bits of data collected from
computers, voice recorders and hundreds of sensors scattered from
Detroit through Canada into New York, officials said.
The retracing of the 600-mile electrical storm track starts at 1
p.m. on Aug. 14. Three hours passed before local problems in the
Midwest grew into a crisis that cost billions of dollars and
darkened the homes of millions of people.
Industry officials involved in the inquiry said they were not
prepared to point to a particular cause, human or technological, but
they generally voiced enthusiasm for the pace and progress of the
"We think we have the timeline nailed pretty well," said Donald
M. Benjamin, vice president of the North American Electric
Reliability Council, the industry group created after the 1965
blackout to maintain electricity flows.
"It's down to the second in terms of what happens, which
transmission paths opened, when areas became isolated," Mr. Benjamin
said. "It provides a good understanding of how the power flows."
But an expert from the federal government taking part in the
investigation was much more definitive about a probable cause,
saying all the data pointed to mistakes by people in the event's
The crucial missteps, a federal investigator working on the
analysis said last night, appear to have occurred in the handling of
an hourlong sequence of line failures and plant shutdowns preceding
the full-blown blackout, which swept parts of eight states and
eastern Canada starting around 4:10 p.m. on Aug. 14.
"Had all of the existing policies been followed, this would not
have developed into a cascading event," the investigator said. "What
we see are institutional breakdowns, not a breakdown of the system
He and other investigators declined to discuss details, but
others involved in the investigation said the timeline essentially
matched independent analyses done recently by several grid experts
The chronology also shows that by the time the problems left the
Midwest, the disruption could not be stopped from exploding through
the large portals linking that region with Canada and then with New
The reliability council, also called NERC, assembled the record
for its own investigation and for a task force created by the
Department of Energy and the Canadian Ministry of Natural
The findings so far will be discussed today with Spencer Abraham,
the secretary of energy.
Mr. Benjamin said utilities were still assembling records from
earlier in the morning of Aug. 14, with the goal of comprehending
what conditions existed around the electrical grid of wires and
plants before there were any signs of trouble.
Officials at the FirstEnergy
Corporation, the Ohio utility whose territory and lines have
been identified by many experts as the most likely trigger for the
event, yesterday stood by the company's contention that there were
power plant and line failures outside of its territory in the hours
before its own troubles began.
"As far back as noon, there were other generation-unit trips and
other transmission-line trips outside of our area," said Ralph
DiNicola, a spokesman for FirstEnergy. "We're certainly hopeful that
the Department of Energy and NERC are looking at all of those
Yesterday, officials from the Midwest Independent Transmission
System Operator, the group responsible for overseeing the safe flow
of electricity around the Midwest, said they remained convinced that
the group had not contributed to the cascade.
In the Northeast, officials said they were still unable to answer
some basic questions about how and why the blackout spread from the
Midwest and Ontario into New York, both across the major web of
transmission lines that cross the international border at the
Niagara River, and at a bottleneck in upstate New York that
separates the eastern part of the state from the western part.
In both places there are relays — essentially large versions of
the circuit-breakers in a household fuse box — along the lines. When
something goes wrong, the relays are supposed to trip, interrupting
the flow of current, protecting other equipment from damage and
keeping the problem from spreading.
Yet officials say many relays — which are owned by the New York
State Power Authority and Niagara Mohawk, a major upstate utility —
continued to conduct power even as the system gyrated out of