While an investigation into a wreck that killed two brothers from Flowery Branch is ongoing, Gwinnett County Police say they believe the cause may have been speed.

Paul Keys III, 23, and his brother Shawn Keys, 19, were both killed early Sunday in a wreck on Interstate 985.

Police who responded to a call of a vehicle on fire in the woods off the shoulder of I-985 southbound just inside the Gwinnett County line found a Honda CRX fully engulfed in flames.

The crash occurred sometime between 1 and 2 a.m., Gwinnett County police spokesman Cpl. David Schiralli said.

Schiralli said both men were dead when emergency responders arrived at the scene. The exact cause of death will be determined by a medical examiner.

The investigation into the cause of the wreck is not complete and could take days as police gather information from possible witnesses and reconstruct the accident. However, evidence at the scene has led investigators to believe the brothers were traveling at a high rate of speed before the accident, said Brian Kelly, another spokesman for the department.

Schiralli would not say exactly how long the investigation is expected to take.

“Each (investigation) takes its own time,” he said.