DEER PARK, TX --A Dickinson ISD bus driver was fired amid allegations of sex crimes involving two young girls. David Ray Tyler, 54, was arrested Monday on a charge of continuous sexual abuse of a child, according to a Harris County probable cause document. Tyler is accused of sexually assaulting one girl on Monday and another girl a month earlier. Both girls are under the age of 14. Tyler, who worked as a bus driver at Dickinson ISD, was fired Tuesday after Deer Park police contacted the school district and notified them of the ongoing investigation. Dickinson ISD says it has no indication that either of the incidents occurred on or in school property or while Tyler was on duty. It also noted that the alleged victims weren't students of Dickinson ISD. Tyler's bail has been set at $50,000.