The accident happened on the northbound Roosevelt Boulevard near Levick Street around 12:30 this morning.
A BMW slammed into a tree, and flipped, after colliding with a Nissan.
Investigators say the driver of the Nissan made an illegal lane change from the outer to the inner lane when it was struck by the BMW.
Two people are now in the hospital, but both are expected to fully recover.
Formal charges have yet to be filed. Police are still investigating the case.