An explosion and fire at a house in Masonville last night injured three people. One victim suffering from facial burns was transported by medical helicopter to a hospital. The condition of the other two occupants has not been made available. The explosion happened about 9:15 p.m last night on State Route 206 at a two-story house near Delaware County Route 35. The dwelling was fully involved with fire when firefighters pulled up. Investigators will work to determine what caused the blast and the fire.