BOSTON (CBS) — A man is dead after police pursued him into Chestnut Hill, from a shooting scene in Boston where a Brigham and Women’s Hospital valet was seriously injured. The deadly police-involved shooting happened on Route 9.

Boston Police initially responded to a 911 call for a person with a gun at 60 Fenwood Road around 9:20 a.m. Friday. That is where they encountered the suspect, identified as 41-year-old Juston Root of Mattapan.

“The suspect pulled out and pointed directly at the responding officers what appeared to be a firearm,” Boston Police Superintendent-in-Chief Greg Long said at a news conference. “At this time the officers discharged their firearms at the suspect.”

The suspect then “physically assaulted” one of the officers on the ground and was able to flee the scene.

WATCH: Video Appears To Show The Suspect Fleeing Police

Long said police are still investigating the circumstances that led to the valet being shot near the hospital entrance. I-Team sources said the 49-year-old man was shot in the head. According to Brigham and Women’s, that man was in serious, but stable, condition Friday afternoon. He was listed as being in good condition Saturday.

It is not clear why the suspect was at the hospital. Sources tell WBZ’s I-Team that Root has a history of mental illness.

A man who was evacuated from Brigham & Women’s during the chaos described the scene. “So many people and it was confusion,” he told WBZ’s Beth Germano. “People screaming, people running, it was a mess…. They [hospital staff] just said rush out of here.”

“It was chaos, cops everywhere,” said Tammy Tene, who lives across the street.

She said she heard “at least 15 or 18 shots. It was like one after another. Everybody was running all over… He got in a car. The cops started chasing him.”

Witness Justin Heitmann recorded video of the suspect fleeing police outside the hospital.

“Hobbling back to his car, you know as the police officers had their guns drawn, saying ‘Get down! Drop your gun, drop your gun!’” Justin Heitmann said. “And he wasn’t obeying by that.”

Police followed Root until the pursuit came to an end with a crash on Route 9 in Chestnut Hill. Long said Root got out of his car and pointed what appeared to be a gun at police.

“After ignoring multiple commands to drop what appeared to be a firearm, multiple officers, including a Massachusetts State Trooper, discharged their firearms,” Long said. The suspect was pronounced dead at a local hospital.

A smashed gray car was visible at the Chestnut Hill scene. Witnesses told WBZ-TV there were several more damaged cars up the street.

The first car Root hit was being driven by Hilary Maddox. “All of a sudden I felt a tremendous bump on the side,” Maddox told WBZ. “I saw a car going like 200 miles per hour by me. And he went up on the curb and went between three other cars, completely smooshing them on the way. Kind of flipped and went through the intersection and crashed into a post on the other side.”

Some police officers and troopers were taken to hospitals for evaluation but have since been released.

A portion of Route 9 was shut down most of the day while police gathered evidence and awaited a search warrant for the suspect’s vehicle.

Brigham & Women’s Hospital released a statement saying:

“Brigham Health is tremendously grateful to the Boston Police Department for its immediate response to today’s active shooting incident on the streets outside of our hospital. We are also grateful to our colleagues for ensuring the safety of our patients, visitors and each other. Our colleague who was injured is being cared for by our clinical team and we are confident he is in the very best hands. The hospital is returning to normal operations, but traffic around the hospital remains challenging.”

WBZ-TV Security Analyst Ed Davis said a shooting outside of a hospital is nerve-wracking to the public. “It’s sort of like a church, or like a school in that, it’s a particularly sensitive area. And so the police, the D.A., the people who are responding to this have to be very cognizant of people’s feelings and make sure they understand that they’ve got it under control.”

He added, “This is the kind of pursuit that isn’t optional. When someone uses a weapon and shoots someone, you have to stay with this vehicle and stop the individual before he causes any more damage to people.”

Boston Mayor Marty Walsh wished the valet a speedy recovery.

“He’s in one of the best hospitals in the world,” Walsh said.

Anybody who was affected by the incident or who might have information is asked to call police.

Editor’s Note: An earlier version of this story indicated a second person was in the suspect vehicle. Sources later confirmed that was not the case.