"You heard a little tire screeching, swerving...then it sounded like a shotgun went off," said David Lewis, who was just five feet away from Hare as she walked down the street while talking on her phone.
The Indian River Estates neighborhood has no streetlights, and no sidewalks.
"He hit her so hard she flew from my house to three houses down," added Lewis.
For most of Monday, investigators had a section of Palm Drive closed off so they could conduct measurements and try to determine how fast the van driver was going.
Authorities marked the part of the street where Brittany's left shoe was found. Twenty feet away, a marking shows where he right shoe was found.