Hannah Upp was last seen on September 14, 2017, in St. Thomas, U.S. Virgin Islands. Her disappearance occurred one week after Hurricane Irma struck the island, and one week prior to the arrival of Hurricane Maria, which brought heavy rains.

This is not the first time Hannah has gone missing. In August 2008, when she was living in New York City and working as a teacher, she disappeared on the first day of school and was missing for 20 days. She was later found floating facedown in the water near Manhattan, and was treated for hypothermia, severe sunburn, and dehydration before being transferred to a psychiatric unit. It was determined that she had spent the missing time wandering around New York City. Doctors were unable to find any physical ailment, and she was ultimately diagnosed with dissociative fugue, a condition usually caused by psychological trauma.

In 2012, while living in Maryland and working at a Montessori school, Hannah disappeared once again on the first day of school, and was later found in a creek about a mile and a half away from her workplace, having entered another dissociative fugue.

Four years later, Hannah moved to St. Thomas and began working at the Virgin Islands Montessori School. On the day of her disappearance, she left her sundress, sandals, car, and car keys at a local bar, where she often went snorkeling.

Hannah's family and loved ones remain hopeful that she is still alive. Due to her skill as a swimmer, there is a possibility that she may have survived for several days in the water. Some speculate that she may have boarded one of the many boats evacuating the island during the hurricanes and traveled to Florida, the Bahamas, St. Croix, or Puerto Rico. As of now, Hannah's disappearance remains unsolved.