PORTLAND, Ore. -- A woman with a walker was struck by an impaired driver at Southeast 122nd and Division shortly after 5 a.m. Tuesday, police said.

The driver of a BMW, later identified as 25-year-old Weifu Ma of Portland, left the scene but was detained by police a short distance away after assistance from an alert citizen in a truck.

Police said the victim, 70-year-old Linda Babcock, will survive her injuries. She was listed in fair condition on Friday afternoon.

Marco Harrera told KGW that his wife was driving their truck when they saw Babcock get hit in a crosswalk. Witnesses told police she had the walk signal.

“I saw the woman tumble over. Head over heels. Then, the vehicle that struck her didn't even take two looks. Just kept on, like the person didn't even exist,” he said.

When the driver didn't stop, Harrera's wife followed the BMW. The driver actually backed into them several times, Harrera said. They boxed in Ma's car in a nearby neighborhood, and then confronted him.

Ma was so impaired that he did not know he had hit the woman, Harrera said.

“He acted like oblivious of what was going on."

He said the suspect was asking, “Why did you hit my car?”

“He was slurring his words,” Harrera said.

"I've seen several hit and runs. And a lot times, the driver gets away. This time he wasn’t."

Police took Ma to the Multnomah County Jail. He faces charges of felony hit-and-run, reckless driving, fourth-degree assault, driving under the influence and second-degree criminal mischief.

Photos: Woman hit by car at SE 122nd & Division