Teresa Martin has filed suit on behalf of her late daughter's estate against the Crowne Plaza Chicago-O'Hare Hotel for negligence, claiming there were several opportunities for the company and its staff to step in and help prevent Kenneka's death last September ... but failed to do so.

In the docs, obtained by TMZ, Teresa alleges that the hotel was made aware of Kenneka's disappearance from a room where a party was being thrown shortly after she wandered off, and says she was assured by Crowne Plaza personnel that they'd check surveillance footage in an attempt to locate her right away. She says they completely screwed that up.

Teresa says the hotel staff either didn't check the footage soon enough, or didn't properly review it ... because the 19-year-old could be seen clear as day stumbling into the kitchen in video later obtained and released by police who investigated her death.

She goes on to allege that Kenneka walked by several hotel staffers who didn't help her, and that the freezer Kenneka walked into was easily accessible to the public. She also claims the freezer had a faded sticker on it that failed to instruct people on how to unlock the door.

Kenneka's body was found in the freezer nearly 24 hours after she was reported missing. Her cause of death was hypothermia and it was ruled accidental. Tons of rumors swirled around the circumstances of her death, with some suspecting foul play.

Despite the police closing out their investigation without any arrests or charges, Kenneka's mother says the blame still lies with the hotel. She's asking for more than $50 mil in damages.