DECATUR, Ill. (WAND) - An 18-year-old woman who died after her car plunged into Lake Decatur had a blood alcohol concentration over two times the legal limit. 

According to the Macon County Coroner Michael Day, Tabatha Pratt's BAC was .182 percent at the time of her death. The legal limit is .08 percent. 

During the coroner's inquest, Day said no other drugs were found in her system when Pratt died. 

Surveillance video obtained from the scene showed no other vehicles were near Pratt at the time of the crash. 

Family members told police they believe Pratt had been drinking before the crash. 

Pratt died on scene near the 1400 block of S. Franklin Street. She was the driver and only occupant of the car. Officers found Pratt's car in the South Shores area of Lake Decatur near the S. Main Street bridge on Oct. 15. 

Police said Pratt was traveling southbound on S. Main Street when her car left the road, crashing into the lake.Â