EAGLE, Wis. (AP) -- The tornado that hit a southeastern Wisconsin city caused at least $20 million in damage.

Waukesha County spokeswoman Julianne Klimetz says that figure is expected to rise because damage assessment is still being conducted. She expects it to be concluded within a week.

Lori Getter, a spokeswoman for Wisconsin Emergency Management, tells the Milwaukee Journal Sentinel the state may seek federal disaster relief after the damage assessments are done.

A federal disaster declaration will allow governments to recover costs of response services and could assist residents who have no insurance and businesses.

Eagle's sirens failed to sound and officials are still trying to determine why the sirens failed.

Waukesha County officials have said at least 25 homes were destroyed. Gov. Jim Doyle has declared a state of emergency.