It happened Monday morning in the 200 block of North West 16th street.
Captain Craig Akard with the Lawton Police says a woman went to leave in her vehicle when a disturbance broke out between her and the parents of the child.
During the altercation, Police say the child was sitting in the grass away from the disturbance, but at some point moved into the parking lot and behind the vehicle.
When the disturbance ended, Akard says the woman got into her vehicle and backed up, not realizing the child was behind her.
She rolled over the 18-month old.
The boy was taken to Camanche County Memorial Hospital then was brought by helicopter to the Children's Hospital in Oklahoma City.
He later died from his injures.
Lawton PD is still investigating whether the disturbance caused the child's death, if so, criminal charges could be filled.
The Lawton PD is not releasing any names at this point
Copyright 2015 Nexstar Broadcasting, Inc. All rights reserved. This material may not be published, broadcast, rewritten, or redistributed.