KENOSHA, Wis. (AP) - Anthrax scares shut down a middle school and a social services building Tuesday, and authorities in Milwaukee reported the second threat at a city clinic in as many days. Bullen Middle School was evacuated after receiving a letter purportedly contaminated with anthrax, a deadly livestock disease that can be transmitted to humans. A similar letter was received at the Children's Social Services of Wisconsin building. As a precaution, 33 people underwent decontamination procedures at the scene and were taken to a hospital for evaluation. Dr. Gary Zaid, director of emergency medicine at Kenosha Hospital Medical Center, said all indications were that the threats were hoaxes. In Milwaukee, 10 people were taken to a hospital Tuesday as a precaution after one of them opened a letter that contained white powder and an anthrax threat at Aurora Health Care offices. A day earlier, there was a hoax at a Planned Parenthood downtown. The FBI was investigating all of the threats.