BOSSIER CITY, La. -- Twins found dead inside a hot pick-up truck at their Bossier City, La., home on Saturday could have been in the vehicle at least two hours, according to a preliminary autopsy report.
But investigators are still piecing together exactly how they got inside, KTBS-TV reports.
Autopsies conducted Sunday on 3-year-old twins Oliver and Aria Orr show the preliminary cause of death to be heat-related. Police say there was no sign of trauma. The official cause of death has not been released yet.
The children's father is a deputy with the Bossier Sheriff's Office.
Their mother told police she had laid down and later realized she couldn't find them.
Police say in a news release that the mother contacted neighbors Saturday to say she was looking for her children. They were found in the truck outside their home in Bossier City, and emergency workers were called.
The children were taken to a local hospital, Willis Knighton-Bossier Health Center, where they were pronounced dead.
"You can only imagine what the family's going through, the extended family, the first repsonders having to deal with a situation like this. It's tough. A lot of our first responders have children, children this age," said Mark Natale, Bossier City Police Department.
Bossier City police detectives are scheduled to meet with the district attorney to decide what's next for the case.
Sheriff Julian Whittington released a statement saying they are saddened by the tragic loss of Oliver and Aria and ask for prayers for the family.
The Associated Press contributed to this report.