Four people were in the vehicle and at least some of them had to be removed after the early morning crash, Las Vegas police officer Laura Meltzer said.
"It's a pretty horrific scene out here," she said.
All the victims appeared to be adults, and the four people killed were apparently pedestrians waiting at the bus stop, Meltzer said.
Debris and sheet-covered bodies remained on the scene several hours after the crash. Roads were shut down as investigators worked to piece together the chain of events along the busy business corridor lined by fast-food restaurants, strip malls and gas stations two miles west of the Las Vegas Strip.
A police officer who was fueling his vehicle at a nearby convenience store watched as the car appeared to lose control and bottom out on a downward slope before leaving the pavement and slamming into the bus stop, police Sgt. Richard Strader said.
The vehicle, which came to rest in a fast-food restaurant parking lot, was so mangled that authorities initially had difficulty determining its make and model.
The driver survived but has a collapsed lung and possibly a broken back, according to police. He will be tested to determine his blood-alcohol content.
"First responders said they smelled alcohol and he even said something to the effect that he had been drinking," Strader said.
The driver and victims were not immediately identified.
Meltzer said some of the victims were dismembered. The bus stop was flattened and its roof landed 15 feet from the spot where the structure once stood. Newspaper stands and concrete littered the scene.
"It's so tragic because this is preventable," Meltzer said. "This person made a choice."
The four deaths brought the number of people killed in traffic accidents in Las Vegas police jurisdiction to 83 this year.