First they heard the beating on the side of the bus. Then came shock and frenzy as about two dozen CobbLinc passengers realized a person was trapped underneath.

Drea Wilkins said no one really knew what to do when a man on an electric scooter was hit and dragged under the bus in Midtown on Wednesday night. Least of all the driver, a woman Wilkins said was assigned just this week to Route 10, which takes Cobb commuters to the Arts Center MARTA station.

A fellow passenger first heard the thumping as the bus made a right turn into the station on 15th Street from West Peachtree Street.

“We all jumped out the bus and the bus driver is just screaming,” Wilkins told AJC.com. “We were saying, ‘Ma’am, call the police, do something!’ She was in shock that she ran him over.”

Help was not coming fast enough. Wilkins ran into the MARTA station and down to the train platform, looking for the first MARTA police officer she could find. He was the first on the scene, she said.

By the time the rest of the emergency crews arrived, just before 10:30 p.m., it was too late. The rider, identified by authorities as 37-year-old William Alexander of Atlanta, was dead before firefighters were able to free him.

City officials said Thursday that Alexander was heading home from an Atlanta United when he was struck.

Authorities are still trying to determine what happened. Surveillance footage from the MARTA station showed the victim on a scooter before the crash, but it did not capture the moment of impact, according to Atlanta police.

As a result, investigators cannot say if the man was riding the scooter when he was hit, Capt. William Ricker told Channel 2 Action News from the scene Thursday morning. A scooter was found in the street on the bus’s passenger side.

“We're hoping that the actual footage from the bus itself, which has cameras, will paint the real story of how it took place,” he said.

The accident happened at West Peachtree Street and 15th. Police and emergency crews blocked the area near the MARTA Arts Center.

So far, police have not been able to determine who was at fault. Wilkins said it’s common for bus drivers to run up onto the sidewalk at that intersection, as her Route 10 bus did Wednesday night.

She thinks Alexander was riding on the sidewalk, but police have not confirmed that account.

Cobb County contracts with First Transit for the CobbLinc service, and county spokesman Ross Cavitt said officials are waiting on details from the contractor. Arrangements are still being made to turn over video from the bus to Atlanta police.

The bus driver has not been identified.

“We are deeply saddened about the incident involving one of our buses last night, and our thoughts go out to the family of the victim,” Cavitt said in an emailed statement. Cobb County will fully cooperate with Atlanta’s investigation, he added.

The crash is believed to be the second deadly accident involving electric scooters in the city of Atlanta. It comes weeks after police ended a grace period for riders and started enforcing city code, which mandates that scooters be ridden in the street with other traffic, not on sidewalks.

IN-DEPTH:  After period of leniency, Atlanta police now enforcing scooter law

The first death on May 17 also happened near a MARTA station. A man on a Lime scooter was hit and killed while leaving the parking lot of the West Lake station in west Atlanta. The driver of a Cadillac SUV is facing charges in that crash.

RELATED: Driver arrested in Atlanta's first deadly e-scooter accident

Considered an alternative transportation mode for short trips, electric scooters have been growing in popularity in urban areas. The narrow, two-wheeled devices can be rented through smartphone apps that charge by the mile. At least four rental companies operate in Atlanta, including California-based Lime.

It is not known what kind of scooter the man was riding in Wednesday night’s incident.

In a written statement, Atlanta City Councilman Amir Farokhi said more could be done to accommodate cyclists, scooters and pedestrians on the city’s streets.

“When someone dies on our roads, it, in part, represents a failure of design,” he said. “It does not matter whether you are walking to lunch, biking to see a friend, scooting home, or driving to the grocery store, you should be safe as you move around the city.

The scooters have posed problems for local officials grappling with how to regulate them. Some cities, including Alpharetta, Marietta and Norcross, have banned them entirely. Others have moratoriums in place while they figure out what to make of the devices.

CONTINUING COVERAGE: Which metro Atlanta cities have banned e-scooters?

We are working to learn more.

— Please return to AJC.com for updates.