HOUSTON (AP) — An apparent disgruntled worker has been blamed for driving a bulldozer into a Houston auction house and causing $1.5 million in damage.

Officials with Ritchie Bros. Auctioneers are not sure why 52-year-old Lynn Benson of Houston was upset. The lot inspector operates the bulldozer as part of his regular duties.

Nobody was hurt Monday night after the auction business closed for the day and Benson allegedly went on his destructive spree. The building was heavily damaged, including a broken water main and destroyed office equipment.

Benson was being jailed Wednesday on a charge of criminal mischief. Harris County Jail online records did not list an attorney for Benson, whose bond is $50,000.