Steve Neavling

Federal investigators are trying to determine what went wrong when friendly fire resulted in the fatal shooting of the U.S. Border Patrol Agent Nicholas Ivie, the USA Today reports.

A preliminary investigation suggests agents became disoriented while responding to a ground sensor near the U.S.-Mexico border, according to the USA Today.

“There are strong preliminary indications that the death of Ivie and the injury to a second agent was the result of an accidental shooting incident involving only the agents,” the FBI said in a statement.

Officials originally believed other suspects were involved and fled to Mexico, a scenario that authorities say looks unlikely.