Slideshow:The driver of the other car -- Angela N. Michael, 45, of McCordsville -- was pronounced dead at the scene."We found out through statements made at the scene that it was a father, and he had turned toward the back seat to care for his 2-year-old son, who was in a car safety seat," said Fishers police Sgt. Gerry Hepp.But Hughes later told investigators that he had smoked marijuana and had taken sleeping pills, pain medication and anti-anxiety medication before the wreck."He was very disoriented, and it doesn't appear to be a medical condition or an injury from the crash. It is the medication causing him to be impaired and probably causing him to drive the way he was," Hepp said.Hughes' son suffered minor injuries and was released from a hospital. He was placed in the custody of another family member.Hughes was arrested and preliminarily charged with operating a vehicle while intoxicated causing death."Having a situation like that happen is certainly a tragedy, but now you add the fact that we have an impaired driver apparently due to prescription and illegal drug use certainly makes this much more tragic," Hepp said.Hughes failed a series of drug tests, but investigators will wait on toxicology reports to determine exactly which drugs were in his system when the wreck occurred, police said.