The driver of a car that barreled through a building used for a popular after-school camp in central Illinois, killing three children and a teenager, was not under the influence of drugs or alcohol and may have had a medical emergency, police said Thursday. No decisions have been made on whether to file charges against the 44-year-old driver, Illinois State Police Director Brendan F. Kelly said at a news conference. Evidence that she may have had a medical emergency was “not conclusive” and the investigation is ongoing, Kelly said.