WALLIS, Texas -

New information was released in the deadly Father's Day glider crash in Fort Bend County.

The crash happened Sunday near Highway 36 and Cougar Road.

NTSB investigators have not been able to determine an exact cause of the accident, but said they found a temporary wheel attached to the tail of the wreckage. Officials said it should not have been on the plane during the flight.

Fred Blair, 68, along with his 3-year-old grandson, Andrew, and the boy's mother, Matilda Blair, 32, died in the crash.