The victims, described as best friends, were in a car with three other people when it crashed into a tree in Wilmette.
A little after 2:30 Monday morning a vehicle traveling southbound in the 700-block of Sheridan Road struck a tree, killing 18-year-old Veronica Rojas and her best friend, 17-year-old Natalie Stygar, both of Chicago.
Family and friends gathered outside the Rojas home Monday afternoon.
"[Veronica] just turned 18 yesterday. She had a friend coming to pick her up to go out for a birthday party. We all just got calls this afternoon. The detectives came by and told my sister that her daughter was killed in a car accident in Wilmette," said Darrin Tippen, Rojas' uncle.
Tippen's niece, the mother of a 2-year-old, wanted to come back to school to become a nurse, and she was a leukemia survivor.
"My niece survived cancer. She was a good girl. She was a good mom to her child," Tippen said.
Rojas's mother said detectives Monday morning gave her the news that her daughter died in the accident, along with her best friend, and three others survived.
"I just want to tell other parents that they are good kids, but lots of them drink and we don't know, and most likely when they go out for birthdays and graduations they tend to drink, smoke, whatever they do. I plead with other parents, please, keep an eye on your kids," said Deborah Echevarria, Rojas' mother.
Wilmette police have not confirmed that alcohol was involved.
The police say the site of the accident is a dangerous one and there have been a number of accidents in the area recently.
"I was sleeping and heard this loud crash, similar to thunder or something like that," said Al Netter, resident.
Wilmette city officials confirm there have been four accidents in the area over the last three years and that this is the first fatality.