The 16-year-old Northern California girl who was injured in a collision between two personal watercraft in Keehi Lagoon Sunday has died of her injuries, officials said today.

The Medical Examiner’s office was to conduct an autopsy today to determine the cause of death of Kristen Fonseca, of Vacaville, Calif. She died Monday afternoon at the Queen’s Medical Center.

The state Department of Land and Natural Resources is investigating Sunday’s collision between two personal watercraft in Keehi Lagoon that sent two tourists to the hospital. Fonseca’s mother said the girl’s watercraft was rammed from behind.

The other rider, a 20-year-old man, was taken to a hospital in serious condition following the crash, which occurred between 1:30 and 1:45 p.m., DLNR  spokes­woman Deborah Ward said.

Honolulu police have listed the case as an unattended death and said there are no signs of foul play, however they are continuing to investigate the incident.

Both riders had rented the watercraft from Aloha Jet Ski, Ward said.