Six people were injured Tuesday when a rental truck drove onto a sidewalk and flipped on its side in the Chinatown section of Boston, officials said.

Four people were taken to area hospitals and one remains in critical condition, police commissioner Michael Cox said in a news briefing at the scene, near the intersection of Kneeland Street and Harrison Avenue. Two others refused medical attention, Cox said.

“Our preliminary investigation seems to indicate that this seems to be more of a tragic accident than anything else,” Cox said.

The crash happened at 12:48 p.m. Fire officials said the truck struck multiple poles before coming to a stop. Images shared on social media showed glass and other debris scattered across the sidewalk and road.

The driver was trapped inside the truck and had to be extricated, according to fire department radio transmissions posted on Broadcastify.

Cox said the driver was initially listed in critical condition but has since improved. The driver’s name was not immediately released.

Another person remained in critical condition late Tuesday afternoon.

“We’ll do everything that we can to come to a full understanding of the facts of this investigation and make a determination as to whether or not there’s any liability here,” Suffolk District Attorney Kevin Hayden said at the briefing.

“Right now, we’re thankful that people, other than one person, seem to be doing OK,” Hayden added. “This easily could have been a far worse circumstance given the time of day and how many people tend to be in this area at the time.”

A spokesperson for Penske said in a statement that the truck was “out on rent to a commercial trucking company.”

“This is an ongoing situation that we’re monitoring closely,” the statement said. “Penske will be cooperating fully with authorities to support their investigation. Our thoughts are with those who have been injured in this unfortunate incident.”

Boston Mayor Michelle Wu thanked first responders who rushed to the scene.

“This is such a busy part of the city, right in the middle of the day, people going back and forth on their way to get lunch, support our small businesses, and carry out their daily routine,” she said. “It is quite shocking to see the scene as it stands right now and just the scale of damage.”

After the crash, a heavily damaged Penske box truck was resting on its side on the sidewalk, wedged between a telephone pole and a building on Kneeland Street. The building had several shattered windows.

Wu said the inspectional services department will assess the building’s condition.

Police sent two cruisers to the scene, but before they arrived, an officer who had viewed the crash on a camera alerted a dispatcher, according to radio transmissions.

“Ma’am, it’s pretty bad,” he told the dispatcher. “Start H and H immediately. Start EMS. There’s a box truck into a building.”

H and H is a reference to City Health and Hospitals, which formerly oversaw ambulance service in Boston.

Police closed Kneeland Street between Tyler and Washington streets as they investigated the crash, Marron said.

Gloria Rodrigues, a Boston resident, said she was nearby at the time and heard the crash. She rushed over and saw a frantic scene.

“The truck was on its side and everyone was running,” she said.

She said she saw some people lying on the ground, including one person who appeared to be unconcious.

“Some of the people on the ground were moving but they looked like they were in pain,” she said. “I’m pretty shaken up … you just don’t see that every day.”

Nick Stoico can be reached at [email protected]. John R. Ellement can be reached at [email protected]. Follow him @JREbosglobe. Sarah Mesdjian can be reached at [email protected]. Follow her on X @sarahs_journal.