30 Davis Boulevard and was proceeding to back out of the driveway, Hegarty said. Rivers was walking along the sidewalk when the garbage truck apparently knocked her down and ran over her, he said.

The driver jumped out of the truck and attempted to provide medical aid. Rivers was pronounced dead at the scene after police arrived.

Rivers retired from teaching at Tampa's Memorial Middle School in 2016. She taught business technology to seventh and eighth graders and always had a positive attitude, said assistant principal Tehia Robinson.

"She was nothing but sweet," Robinson said, describing her former colleague as mild-mannered and funny.

Deborah Moseley taught with Rivers at Aparicio-Levy Technical College in Tampa before her days at Memorial.

Moseley said her friend would walk around the campus singing Moves Like Jagger, andthe two stayed in touch when they were no longer colleagues.

"She was one of a kind," Moseley said. "She had a big heart and was always willing to share."

Moseley said she was shocked by the suddenness of the loss and hoped to learn more about how it happened.

The investigation into Rivers' death was still active as of Wednesday afternoon.

Mercer was reprimanded in 2015 for a crash involving his solid waste truck in December 2014, according to his city personnel file.

When exiting a parking lot on Broadway Ave., Mercer failed to yield to a car, causing the car to collide with his truck, the record states.

In that case, the car's driver was transported to the hospital with minor injuries. A review by the city's Department of Solid Waste Incident