A Middletown man was injured today in a house explosion in the 2500 block of Flemming Road. Fire Chief Paul Lolli said when firefighters arrived, the back of the house was on fire and was “blown up.” He said the man inside the house said he heard a loud bang and then saw flames. He escaped the house, but suffered “pretty significant injuries,” Lolli said. The man was taken to Atrium Medical Center for treatment and then taken by medical helicopter to Miami Valley Hospital. Middletown police are asking residents to stay out of the area and find alternate routes. Lolli said the investigation continues and the cause of the explosion may not be determined until Tuesday.