ROCKLEDGE, Fla. -

Police on Friday arrested the father of a 9-month-old girl who died after being left inside a hot vehicle for hours.

Steven Lillie was arrested on charges of aggravated manslaughter in the death of his daughter, Anna Marie Lillie.

Lillie found his daughter unresponsive Monday in his pickup truck outside his workplace on Barton Boulevard in Rockledge.

Police said the girl had been left inside the closed truck for about four hours during the hottest time of the day.

Police believe Lillie arrived at work sometime after 1 p.m. Monday. They found the child in her car seat in the backseat of the truck, and although the windows were tinted, they were rolled up.

Paramedics rushed the girl to Wuesthoff Hospital, where she died.

Police on Tuesday said Lillie left for work intending to drop his daughter off with a caregiver.  Some type of disruption in Lillie's normal routine, however, caused him to forget that he had not dropped off the baby, police said.  About four hours later, a family member asking about the girl prompted Lillie to run outside, where he found his daughter inside the truck, police said.