New York Gov. Andrew Cuomo, in a letter to utilities, warned of consequences if authorities discover they failed to prepare properly.
"Under such circumstances, I would direct the Public Service Commission to commence a proceeding to revoke your certificates," he wrote.
Under scrutiny, the New York City Marathon -- scheduled for Sunday -- was canceled, the city's mayor said Friday.
"While holding the race would not require diverting resources from the recovery effort, it is clear that it has become the source of controversy and division," Mayor Michael Bloomberg said in a statement.
"We cannot allow a controversy over an athletic event -- even one as meaningful as this -- to distract attention away from all the critically important work that is being done to recover from the storm and get our city back on track."
The superstorm also dumped up to 3 feet of snow in West Virginia and Maryland, leaving thousands without power.
The National Weather Service predicted a nor'easter next week from the mid-Atlantic states into New England. But the forecast said the storm would be far weaker than Sandy.