Five people were killed when a small plane went down on the highway that connects Mexico City to the city of Queretaro, the communications and transportation secretariat said.The twin-engine M3 aircraft belonging to Aeronaves TSM crashed at 2:35 p.m. on Tuesday while on a test flight near the Bernardo Quintana Industrial Park, the secretariat said in a statement.The crash happened "a short time after take-off" and the cause has not been determined, the Queretaro Intercontinental Airport control tower said.The highway was closed on the Mexico City-Queretaro side so emergency services personnel could access the crash site.Firefighters, federal police officers and army troops responded to the crash.