LEVELAND, Aug. 21 — The huge gray cooling tower of the Davis-Besse power plant stands along Lake Erie like a monument to nuclear energy and industrial might. That it has been idle for more than a year, though, makes it a testament to something else, according to former employees and the federal regulators who ordered it shut down.

The dormant plant, for them, is an example of neglect and poor management by its owner, the FirstEnergy Corporation, which allowed hazardous conditions to fester so badly that a catastrophic accident may have been only months away.

The shutdown of Davis-Besse — the plant, outside Toledo, was taken off-line after acid nearly ate through the reactor lid — is the most extreme example of shortcomings in how FirstEnergy runs an empire with 4.3 million customers across New Jersey, Pennsylvania and Ohio.

But it is not the only one.

Its New Jersey subsidiary has come under fire for frequent blackouts, for inadequate maintenance and for allowing stray electricity to run through the ground, leaving residents of Brick, N.J., tingling when they step into pools and Jacuzzis.

And in northern Ohio, mayors have complained to state regulators that power failures by FirstEnergy have become more frequent and longer, forcing some to buy diesel-powered generators for municipal buildings. The company has been responsible for more blackouts in Ohio already this year than all of last year.

When FirstEnergy's network of transmission lines and power plants in northern Ohio failed last Thursday — one of the first problems in the cascade of events that resulted in the nation's largest blackout — misgivings among elected officials and others about the company's performance turned into wider and more fundamental questioning of its conduct as one of the major players in the nation's deregulated, physically vulnerable energy market.

FirstEnergy contends that its run of recent problems is not the result of a systemic management failure or inadequate investment in its power system, and some industry monitors assert that the company's performance is by and large no better or worse than other giant utilities.

FirstEnergy has failed, it said, to meet national standards for safe operations in very few categories.

And the federal officials investigating the blackout have been explicit in cautioning against assuming who, if anyone, was to blame, and emphasizing that it will be weeks before they sort out what exactly accounted for the failure of any part of the system.

FirstEnergy, based in Akron, is no Enron, the once high-flying Texas energy merchant that sold its power plants at the dawn of energy deregulation to focus on buying and selling power. Formed in 1997 by the merger of two Ohio utilities, FirstEnergy kept its smokestacks and power lines. But the company is in many ways emblematic of how traditional utilities have tried to adapt to the freewheeling ways of deregulation.

It has become aggressive about expansion, but a number of its senior managers stepped down or were reassigned while the company was under fire. It, like similar energy companies, has invested ever larger amounts on lobbying and political campaigns, pouring money into local and national politics and earning victories on rates and energy policy.

And, documents indicate, FirstEnergy has made what many experts and elected officials regard as less than impressive efforts at spending on the things that they say the nation's electricity grid needs most: upgrading its transmission system. In the three years since deregulation legislation passed in Ohio, its spending on maintaining its high-voltage transmission lines in Ohio has remained all but flat.

The decision not to increase such spending came as industry groups and government regulators were warning that the grid system in the Midwest, including FirstEnergy's territory, could become a choke point in a summer power surge.

FirstEnergy has insisted it was an accidental player in the blackout, that the problem began elsewhere. But many experts say the problems at FirstEnergy are indicative of broader issues affecting many power companies as competitive pressures have increased the drive for profits, and the role of government to police the operation of the nation's power grid is extremely limited.