An alert citizen helped King County Troopers catch a 17-year-old DUI driver from Auburn this morning after she crashed into a guardrail on northbound I-5 in Federal Way.

The collision happened at 7 a.m., when the driver drifted off the road and struck the guardrail near the Federal Way truck scales. After damaging 15 feet of guardrail and puncturing her front tire, she drove away in an attempt to get to her home in Auburn.

A witness followed her until her 1997 BMW became disabled on the off ramp to South 320th Street. The witness called 911 and reported the hit-and-run while staying with the vehicle until troopers arrived and made the arrest.

The juvenile first told the trooper that she fell asleep behind the wheel before admitting she had been drinking alcohol. Her BAC level registered at a .084, which is four times the legal limit for a minor.