The incident happened just after 10 a.m. Wednesday in the 2600 block of SW Thistle Street, which is near Chief Sealth High School.
"All of a sudden you hear, 'Boom! Boom!' " said witness Thomas Terry. "And I see two bodies just fly up in the air; the car just drove off like they didn't even care. It had to be going at least 60, 65 (mph)."
The victims, 18-year-old Cassandra Goodwin and her 17-year-old friend, were taken to Harborview Medical Center. Goodwin was originally listed in critical condition but was upgraded to serious condition later Wednesday. The 17-year-old was expected to be released Wednesday evening.
"(Goodwin) couldn't move and she couldn't breathe," said her sister Amelia Pryer. "And from what the doctors say she has internal bleeding in her head."
Police and witnesses say it started with an argument over the driver's dog.
"The dog jumped on Cassandra, Cassandra hit the dog," said family friend Chelsea White.
Witnesses say the woman became angry when she thought Cassandra hit her dog, who'd gotten loose from her home across the street from the school.
"(Goodwin) apologized after she hit the dog," White said.
The woman and the girls argued, and witnesses say the woman then upped the ante.
"She brought out a Taser chased us with a Taser," White said.
The victims' friends say the girls ran towards the high school.
"(The driver) came around the corner -- she purposely drove her car a certain way so she could hit Cassandra," White said.
Police are still searching for the driver, who drove away after the crash in a black Honda.
Later in the afternoon, Seattle police said the driver called 911 to say she would surrender at 4 p.m., but the time passed with no surrender and she remains at large.
Anyone with information about her location is asked to call 911.