According to the Chicago Tribune, Wells missed a scheduled pickup in Champaign when he returned to Chicago last Friday. The trailer of the 18-wheeler was apparently empty when it slammed in to the CTA Red Line Chinatown/Cermak station.
Investigators are awaiting results of expanded tests to see if Wells may have taken any drugs. Wells did pass a blood/alcohol test. But the Sun-Times reports that police found another person's prescription drugs with Wells.
Investigators are also examining the truck's brakes to make sure it was working properly. The truck apparently left no skid marks as it barreled down the Dan Ryan exit ramp.
The crash injured more than a dozen people and killed two women -- 47-year-old Elosia Guerrero and 18-year-old Delisia Brown. Brown was shopping for a prom dress. Guerrero, who worked at The Sutton Place Hotel, was on her way home.
Police have cited Wells for negligent driving. Criminal charges could be filed soon.