At 2.54pm on Friday, the Clewiston Monitor Department responded to a call about the incident. A four-year-old boy was found barren at the scene and his five-year-old sibling is in critical condition.
The older sibling is bear treatment at Hendry Regional Hospital after being airlifted to a trauma nucleus for treatment.
Clewiston police confirmed a handgun was used in the shooting.
The daughters were found inside a car.
The children’s parents are “torn up”, according to Hendry County Sheriff, Steve Whidden, but ration investigators.
He said: “We are offering our sincerest condolences to the family of these children children.
“We are determined to provide every resource available to us to conduct this discovery procedure to determine how this tragedy could have occurred.”