At least one person was killed Sunday evening when a small airplane crashed into a vacant house in the U.S. state of Oklahoma, officials said.A sheriff\'s deputy had confirmed that at least the pilot was killed in the crash that occurred in the Oklahoma city of Collinsville, according to the news website newsok.com.Officials did not know immediately how many people were in the plane\'s wreckage, the report said.However, other reports said there may be multiple fatalities in the crash.Collinsville Police Chief Jimmie Richey told the Tulsa World that more than one person was killed, but he didn\'t give a specific number.A spokesman for the Federal Aviation Administration said as many as three people were dead, according to local TV channel KOKH-TV.The single-engine aircraft departed Tulsa in northeastern Oklahoma around 5:50 p.m. (2350 GMT) Sunday en route to Manhattan, Kansas. The plane crashed inside the city limits of Collinsville, about 30 minutes northeast of Tulsa, according to reports.No people on the ground were injured, officials said.