SANTA ANA, Calif. -- A 10-year-old girl was found dead in Santa Ana on Sunday afternoon after apparently taking her own life, prompting a police investigation of possible bullying, authorities said.The deceased girl was discovered by her 9-year-old sister, according to the Santa Ana Police Department."We have heard rumors of bullying and are looking into that aspect," a police spokesperson told ABC7. "This is an ongoing investigation and we will be looking into the victim's phone to identify whether there was any bullying."Crisis counselors were on site Monday at Hazard Elementary School in Santa Ana, where the victim was a student. The counselors are expected to remain at the campus throughout the week, accompanied by a police comfort dog."We are deeply saddened by the tragic passing of one of our students," the Garden Grove Unified School District said in a statement. While police are "conducting a thorough investigation, we have no evidence to support" rumors of bullying, the statement added.The district noted that Hazard Elementary School "has a longstanding PBIS (Positive Behavior Interventions and Supports) program and takes a positive approach to promote positive school culture."