Firefighters had stopped at a parking lot at about 7 p.m. to ask for directions to a call and as they left, they struck the woman, Gilstrap said. The woman was knocked off the chair into the street and was declared dead at the scene.
Gilstrap told the San Antonio Express-News for its Monday online editions there was no identification on the woman.
When firefighters saw sparks behind the truck they realized it was dragging a wheelchair and called dispatch.
After learning that a pedestrian had been hit on the street where they had come from, they immediately returned to the scene, Gilstrap said.
The driver of the brush truck and several witnesses were taken to police headquarters for questioning.
