COLLINSVILLE, OK (CNN) -- Federal investigators are trying to figure out what caused a deadly plane crash in Oklahoma.
A spokesperson for the federal aviation administration says the single-engine plane crashed into the backyard of a vacant home in downtown Collinsville Sunday evening.
Air traffic control reportedly lost contact with the plane about seven minutes after takeoff from Tulsa International Airport.
Witnesses say it was obvious the plane was in trouble ahead of the crash. Witness Debra Thompson says, "I look up and I see the plane coming down in a dive. I hear it in a dive, and it was going really fast and then it hits the ground and flames shoot up. It was a big explosion."
The aircraft is identified as a Mooney M20. According to FAA records, the aircraft is registered to Ronald and Rhen Marshall, of DeWitt, Nebraska.
Authorities have not released the names of the victims.