Officers say one driver hit a tree on Pleasant Valley Road and Syracuse Drive around 9:30 p.m. Sunday.
Another driver pulled over to help - and that's when a third driver hit two people from the second car.
One woman was killed at the scene and one man was seriously injured.
That third driver fled the scene on foot.
About an hour later, a resident on Walden Street called police to report an injured man was on the home's roof.
He was detained and given medical treatment. Police were working to confirm if he was the driver involved in the crash.