The plane, a twin-engine Beechcraft BE-350 King Air, crashed shortly after take-off at Addison Airport.
It veered into the hangar before bursting into flames, a local fire department official said.
Darci Neuzil, the airport’s deputy director, said it took off around 0900 local time (1500 GMT), bound for Florida.
Emergency services were quickly on the scene, around 10 miles (17 km) north of Dallas, but there were no survivors.
Authorities have not released the identities of the victims, whose next of kin were being sought.
“I visited the scene and was briefed by incident command. Please pray for the families who lost loved ones in this tragedy. Team in process of notifying them,” Dallas County Judge Clay Jenkins tweeted.
Video footage shows columns of thick black smoke billowing from the hangar. No-one was inside when the aircraft plunged through its roof.
The accident left a gaping hole in the side of the charred building.
Unnamed sources told CBS that the plane suffered engine failure, but this has not been officially confirmed.
The National Transportation Safety Board is investigating.
