said alerted officials to Rivera’s failure to return to the vessel.In the call, a woman can be heard telling the operator “we have a missing person” after stating the location of the emergency as Lake Piru.“We found a little girl in one of the boats by herself and her mom’s nowhere to be found,” the woman continues, apparently misidentifying Rivera’s son.The sheriff’s office said Rivera and her son had rented a pontoon boat and were seen heading north onto the lake. The boy was later found asleep in the drifting boat and he told officials that he and his mother had gone for a swim but only he got back on the vessel.Authorities searched for Rivera, who appeared in the TV series Glee, on Wednesday but by Thursday the mission had become a recovery operation as she was presumed dead. Credit: Ventura County Sheriff’s Office via Storyful">