ROCKTON, Ill. (AP) — A northern Illinois high school’s 59,400-square-foot dome sporting facility has collapsed. The Rockford Register Star reports that it’s unclear what caused the damage to the Hononegah High School dome, which collapsed Monday during a winter storm. The Rockton dome is 13-years-old and is usually used to host sporting events, gym classes and community events. School Board President Dave Kurlinkus says the dome is designed to have snow slide off. He says an investigation into the cause of the collapse is focusing on ice. The New York company that designed the dome and the school district’s insurance company are to inspect the deflated dome Tuesday. Kurlinkus says replacing the dome could take between three and four months. He says it wouldn’t take as long if the dome only needs repairs.