Lansing's Oak Park YMCA will be closed Friday after a carbon monoxide leak forced the building to be evacuated Thursday evening. Two people reported feeling light-headed and weak earlier in the day. They were tested at Sparrow Hospital, which told the YMCA staff to clear the building after they tested positive for the colorless and odorless gas. Lansing firefighters believe a faulty heater caused the leak. The YMCA recommends anyone who was in the building Thursday get checked out, especially pregnant women and the elderly.