The incident with the garbage truck that killed a Baltimore sanitation worker Friday was the result of what is believed to be “driver error,” according to two sources with direct knowledge who were not authorized to speak because of the ongoing investigation.

Timothy Cartwell was working in a driveway along the 1800 block of Baker Street around 10:30 a.m. as part of a three-man crew when the garbage truck driver backed into him, pinning him to a utility pole. wooden light, sources said. The driver, who has not been named, did not know Cartwell was behind the garbage truck, the sources said.

“The circumstances surrounding the death of Bureau of Solid Waste worker Timothy Cartwell remain under active investigation by the Baltimore Police Department,” DPW spokeswoman Jennifer Combs said via email. “We are cooperating fully with the BPD investigation to ensure a full and accurate understanding of what happened.”

It is unclear what training or operating procedures are required for DPW garbage truck drivers.

A police spokesman had no further information to share.

Garbage trucks have significant blind spots due to their design. Some newer city trucks have rearview cameras, but this one apparently doesn’t, according to sources.

Payroll records show Cartwell was a longtime DPW employee who had worked in sanitation since at least 2007.

Friday’s incident marked the second occupational death of a Baltimore sanitation worker in about three months. Ronald Silver II died in August of heatstroke, prompting outrage from unions and some City Council members. Mayor Brandon Scott hired a Washington law firm to review DPW’s workplace safety policies and company report found that the agency had no plan to deal with heat illness.

That report found that employees who reported unsafe conditions feared retaliation from their supervisors, including more onerous working conditions or being assigned degrading duties.

AFSCME Maryland Council 3, the union that represents employees at several city agencies, issued a statement over the weekend saying Cartwell’s death showed “much more needs to be done” regarding workplace safety.

“We have requested a variety of health and safety information from the city, as well as negotiations to improve workforce training and protection,” the statement said.

Soon-to-be City Council President Zeke Cohen said he would direct the council to “find answers” about Cartwell’s death and hold DPW “fully accountable.”

The Scott administration is aware of the myriad problems plaguing the public works department and has promised improvements. Scott called Cartwell’s death devastating in a social media post.