The Indiana parents of the toddler who fell to her death out of an open cruise ship window in Puerto Rico formally filed a lawsuit on Wednesday against Royal Caribbean Cruises. The parents are accusing the luxury cruise provider of negligence by allowing the window to be opened.

The toddler, Chloe Wiegand fell to her death back in July after her grandfather lifted her to the window on Royal Caribbean’s Freedom of the Seas ship while the vessel docked. She would have turned 2 this week.

Chloe’s grandfather, Salvatore Anello, has been charged in Puerto Rico with negligent homicide. He insists that he is colorblind and was not aware the 11th floor window in the children’s play area was open. Anello is due in a Puerto Rico court on December 17th.