A deadly helicopter crash that killed two Capital Region New York National Guard members and injured another is now the focus of a criminal investigation.

ABC News reports that the Starr County Sheriff’s Office in Texas is conducting the investigation.

The March 8 incident near the U.S.-Mexico border resulted in the deaths of Chief Warrant Officer Casey Frankoski of Rensselaer, and Officer John Grassia of Rotterdam.

Jacob Pratt, a graduate from Rensselaer High School, was severely injured.

The cause of the crash has not been released.