Five passengers, along with the 20-year-old limo driver, were injured.
Four male passengers and two female passengers, ranging in age from 45-64, were in the white Lincoln Town Car.
The driver told Illinois State Police he lost control when he was blinded by the sun just before 7:15 a.m. He said he couldn't see the traffic pattern in front of him. He crashed into a concrete divider, which caused the limo to flip over onto its roof.
"That stretch of I-90 is going directly eastbound. At that point in the morning the sun is just coming up on the horizon so it's just about the right height," said Dave Schmidt, assistant chief of the Elgin Fire Department.
When crews arrived, five people had already removed themselves from the vehicle. Off-duty Streamwood firefighter and paramedic Chris Tierney was four cars behind the limo when he witnessed the wreck. He used a hammer in his truck to break the windows of the limo to help get the injured out, actions he say were just instinct. Tierney says flames were shooting from the hood of the overturned limo.
"I saw the hood of the car come off, I saw the car go airborne, and I saw a big plume of debris," Tierney said.
He says construction workers helped him with the injured as they waited for emergency crews to arrive.
"My training kicked in, my instinct kicked in. I exited my vehicle and everything that I was taught came to mind," he said.
One victim, a woman in her 50s, was fatally injured. Tierney tried to save her.
"We were able to get her out of the car and to the back of the limousine where we had to administer CPR," he said.
When crews arrived, Tierney says five Elgin firefighters worked remarkably fast to secure the scene.
"Because of the traffic jam after the crash, all the incoming ambulances were delayed getting there, so those guys did a lot of work, they did a great job," said Tierney.
He also said he doesn't consider himself a hero and is thinking about the victims.
"Now that I'm winding down, I just pray for the victims and hope they can recover. People's lives changed dramatically today and all I can do is pray," he said.
Five people who were injured and the body of the woman killed at the scene were transported to the Sherman Hospital, a hospital spokeswoman said. Since then, two were treated and released and three more were transferred. Two people remain in critical condition Friday evening.
One person was taken to St. Alexius Medical Center in Hoffman Estates and is expected to recover.
The individual who was killed has not yet been identified.
The accident shut down several lanes of eastbound I-90 Friday morning.
The driver is being interviewed by state police. No charges have been filed. Investigators will look at whether speed or road conditions may have also been a factor.
A police official said there was road construction in the area and may have confused the driver.