A fourth teenager died after a car plowed into a municipal bus stop Monday morning in northwest Las Vegas (search).

Two girls and a boy were killed instantly in the 7:18 a.m. crash on Smoke Ranch Road (search) at Rock Springs Drive, police said.

A girl died a couple of hours later at University Medical Center.

Police said the 34-year-old female driver of a Ford Explorer failed an initial field sobriety test (search) — and might have been under the influence of drugs.

The woman, who was not hurt in the crash, was booked into Clark County jail on suspicion of driving under the influence.

Police said the woman lost control of her vehicle and hit the bus shelter before her vehicle overturned just before the Smoke Ranch overpass over the U.S. 95 freeway.

The scene was left strewn with broken glass and school books.

Smoke Ranch was closed from Tenaya Way to Rainbow Drive while police investigated.