A driver was arrested early Sunday after a vehicle crashed into the Almaden Valley post office in San Jose, setting  the building ablaze.

Authorities identified the driver of the vehicle as Richard Tillman, 44, is the youngest brother of Pat Tillman, the former professional football player turned Army Ranger who was killed in Afghanistan in 2004. Richard Tillman was arrested on suspicion of arson, and was being held at the Santa Clara County jail.

Firefighters were called at about 3am on Sunday to the post office on Crown Boulevard, where they found that a vehicle had plowed through the front of the building. It took them more than 90 minutes to extinguish the fire. No one was injured.

In a statement, the Postal Inspection Service said that it was “investigating the incident as a potentially intentional act,” along with local law enforcement agencies.

The agency also said the driver was “reported to be the brother of” Pat Tillman, a star defensive back for the Arizona Cardinals who left the team to enlist in the U.S. Army after the Sept. 11, 2001, terrorist attacks.

It was not immediately clear whether Richard Tillman had legal representation. His family members declined to comment on Sunday.

“I’m grateful no one was seriously hurt by this senseless act of destruction,” Mayor Matt Mahan said in a statement on Sunday. He also acknowledged that mental health issues could have been a factor.

“Criminal acts require accountability,” Mahan added, “but we also need to commit ourselves to expanding behavioral health treatment and intervening earlier in California to reduce the likelihood that situations like this transpire.”

Pat Tillman was a high-profile representative of a surge in patriotism and interest in military service inspired by the Sept. 11 attacks, forsaking a multimillion-dollar football career to become an Army Ranger. He became emblematic of the steep sacrifice that can come with military service when he was killed in 2004.

Richard Tillman, along with other relatives, publicly challenged the official account of his brother’s death. Military officials originally claimed that Pat Tillman had been shot by Afghan militants before disclosing that he had been killed by friendly fire. (A third brother, Kevin, also served in Afghanistan as an Army Ranger.)

Bernard Mokam, Sonia A. Rao and Rick Rojas are reporters with The New York Times.