The incident happened about 7:30 p.m. in the 100-block of Heather Drive.
Neighbors said that a blue SUV slammed into and then through a home's garage before becoming airborne and crashing into the second floor of the home.
Crystal Lake police said the SUV had been traveling east on Ballard Road and continued through the intersection with Briarwood Road before running off the roadway and into the garage and home on Heather Drive for unknown reasons.
"We heard an extremely loud something. We didn't know if it was a crash, or an explosion, something," said Danielle Leschuk, a neighbor, who was having dinner at a friend's house when the crash occurred. "So we came out and started to walk over this way and eventually saw that a car had flown through this stop sign, through the garage, and airborne into the second story of this house into the bathroom where the person that lives there was taking a shower."
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Police said the driver of the SUV, an adult male, was extricated from the car by Crystal Lake Fire and Rescue and airlifted to Condell Hospital with life threatening injuries. An adult who resides at the home was also airlifted to Condell Hospital with life threatening injuries, police said.
The son of the person injured inside the home said his father was in the shower when the incident occurred. He is severely injured, may need multiple back surgeries and may never be able to walk again, he said early Thursday morning.
"People do speed too much in this area, absolutely. There's tons of kids here, and people do speed a lot, and luckily there was no kids or bikes or anybody else walking by," Leschuk said.
A crane was needed to carefully lift the car out of the home. Crews are in the process o tearing down the garage, and the house is next. Both are considered structurally unstable.