Nassau officials say the wrong assessment data was posted for 18,400 county properties, but the numbers have already been corrected.

Clementine Becker, of Lynbrook, was among the many Nassau residents upset after hearing the county admitted to posting an incorrect assessment roll Wednesday that included errors in homeowners' property tax assessments.

"They really should get it right the first time," she said.

The news also alarmed David Smollett, who owns two houses in Lynbrook. He said he worried his properties were be among the errors.

On Thursday, County Executive Laura Curran apologized for the mistakes, saying:

The errors in the tentative roll are the latest in a series of stumbles in the reassessment process. Those missteps include mistakes in 20,000 disclosure notices and preliminary rather than final numbers posted, along with wrong dates in thousands of online tax impact statements.

Republican Legislator Bill Gayler says the Curran administration is making mistakes because it's moving through the process too quickly.

"Maybe we should slow things down, maybe we should get this right the first time and protect the taxpayers," he says.

On Wednesday, the Republican majority filed a bill to extend the deadline for filing tax grievances from March 1 to April 30. Curran announced Thursday that the Assessment Review Commission agreed to the extension.