Police said a door between the garage and laundry room at a home in the 1300 block of Wentworth was removed from its hinges while items were being moved in.
The door somehow fell on the nearly 3-year-old girl, who's been identified as Iva Lea Potter.
The girl was taken to an area hospital, where she was declared dead.
Police said the girl was a twin.
Shortly after the accident, a girl who says she's Iva's older sister tweeted pictures and a message saying, "RIP to my angel. Being your big sister has been the best thing that's ever happened to me. I love you so much Iva Lea."
Iva's family was moving into the home from Flower Mound, about four miles away.
A lady who babysat Iva and her twin said they're in shock, and a family member says they're asking for privacy and everyone's prayers.