KABUL, Afghanistan -- By now, the billions of dollars spent by the United States on flawed reconstruction projects in Afghanistan have become part of the war's history. The military headquarters that the Marines did not need, the schools for which Afghans had no use, the road that cost $2.8 million a mile -- the list runs long.
In the past year, though, American investigators believe they have found a failed program that may have resulted in the deaths of American soldiers.
The program was intended to keep insurgents from planting bombs in roadside drainage culverts by covering the culverts with thick metal grates. Thousands of the so-called culvert denial systems were supposed to have been installed since 2009.
But investigators say that hundreds, possibly more, were never installed, and that an "investigation is looking into whether this apparent failure to perform may have been a factor in the death or injury of several U.S. soldiers," according to a report on the investigation. The report was provided to The New York Times before its official release on Tuesday.
Investigators found at least one case in which apparently missing or faulty grates resulted in casualties. The report said an Afghan contractor and his subcontractor who failed to do the work had been charged with negligent homicide and fraud by the attorney general of Afghanistan. One of the men is in custody.
If the charges stand up, it will be the first documented case of a contracting failure in Afghanistan directly linked to American deaths.
The report, by the Special Inspector General for Afghan Reconstruction, an internal government watchdog, described how overlapping commands could not properly monitor contractors to ensure that work was done on the grates, which cost from $800 to $6,500 each to make and install.
The difficulties are symptomatic of what critics have called mismanagement that has plagued the broader American effort to rebuild Afghanistan and, by extension, the war effort.
Since 2002, the United States has spent roughly $90 billion on relief and reconstruction projects in Afghanistan. Much of the spending took place in the last few years, as American commanders embraced a strategy that depended on building popular support for the Afghan government.
But as a result of poor management, many high-profile reconstruction projects intended to help win over Afghans have created the opposite effect, critics say, raising expectations, then dashing them when the projects failed to meet expectations or simply failed.
The $2.8 million-a-mile road was among those, as was a $400 million fund to bring affordable electricity to a wide swath of southern Afghanistan, much of which remains reliant on a spotty power supply or mired in darkness at night.
The program to protect culverts with metal grates appears to have suffered the same poor oversight as the larger projects that commanders once hoped would tip the strategic balance in Afghanistan.
Citing the continuing investigation, neither the inspector general's office nor American military or Afghan officials offered any details on the deaths that may have been caused.
But Senator Bob Casey, Democrat of Pennsylvania, called the investigation's preliminary findings "disturbing."
Mr. Casey, who has helped lead Congressional efforts to cut the supply of ammonium nitrate fertilizers often used by Afghan insurgents to make hidden bombs, said it was dismaying to see what amounted to "contract administration problems" undercut efforts to counter the threat of so-called improvised explosive devices.
The countermeasures include a troop-carrying vehicle introduced during the Iraq war and the development of hand-held radar devices for soldiers and Marines patrolling on foot.
It is "frustrating to see all of that innovation that was brought to bear on the problem," he said, "and then something as simple as putting a grate over a culvert becomes a huge problem."
Col. Jane Crichton, a military spokeswoman in Afghanistan, said the contracting command here had recently introduced quality assurance experts and policy guidelines to better oversee projects. Commanders were also trying to locate all the installed culvert protection grates and ensure they were working.
The investigation, conducted with the military's help, had not determined precisely how many grates were supposed to have been installed, or even how many contracts were awarded, the report said. Contracts were handed out by different commands, and many records were incomplete or nonexistent.
But investigators were able to identify at least 2,500 so-called grid points where culverts were supposed to be covered.
Hundreds, maybe more, never were. The two Afghan men facing criminal charges were alleged to have not built or to have improperly installed 250 culvert denial systems in a single province. Officials did not specify the province, citing security concerns.
Many of the records that investigators did examine contained no evidence -- photographs, for example -- to verify completed work, the report said.
Problems with the culvert protection program were first raised publicly last year by the inspector general's office, which sent an "alert letter" to the military.
Afghan officials on Monday corroborated the inspector general's assessment. On Highway 1, a road intended to connect all of Afghanistan's major cities, 170 to 180 culverts have been destroyed by hidden bombs, said Ahmad Shah Wahid, the deputy minister of public works.
Sections of Highway 1 were barely passable a decade ago, and Western officials have often cited the rebuilding of the road as a relative success.
Yet in Maidan Wardak Province, which lies directly south of Kabul, insurgents have destroyed 56 culverts along a section of the highway that provides the main route connecting the capital with the areas of southern and eastern Afghanistan where the insurgents are strongest, Mr. Wahid said.
Jawad Sukhanyar contributed reporting.
This article originally appeared in The New York Times.