BONDURANT, Iowa (AP) — A small Iowa school district is scrambling to cover a nearly $900,000 loss after officials failed to account for a big property tax break given to Facebook for its massive data center east of Des Moines. The Des Moines Register reports that Facebook’s fourth data center in Altoona is exempt from taxation for 20 years as part of a development agreement Facebook signed with the city. Exemptions also were granted for the first three centers.

But the Polk County assessor’s office says it was never notified about the exemption and included the $52.4 million building in the tax base numbers provided in 2018 to the Bondurant-Farrar school district and other taxing authorities. The error was caught this year.

Now the district must pay back the erroneous windfall, which officials say amounts to about 3.5% of its budget.