The other news, a frightening scene at a San Francisco high school. Four students shot as classes were letting out and Adrienne Bankert has the search for the suspects this morning. Reporter: A terrifying shooting outside this high school in San Francisco. Fire inside the school. But unknown exactly. Reporter: Gunshots erupting. Four students shot in the parking lot. When officers responded immediately they thought this was an active shooter because they saw the victims inside the school. Reporter: Panicked students running in the chaos, many going back into the school for safety. Everybody pushed our desks and we went under to make sure we were safe. I saw people running through the hallway. Reporter: The campus on lockdown. This morning a 15-year-old female student remains in critical condition. I could tell thaw this was not just a random shooting and that the suspects didn't come here just to randomly shoot at any of the students. Reporter: Police now searching for four male suspects who they believe came to the school to target one of the victims. It's still like terrifying like I don't want to see this going on. Reporter: And, David, one of the students not initially treated here at the scene later walked to a police station. We know that he and two other victims have since been released from the hospital and that when classes resume this morning there will be additional staff on hand for those students, David. Just a horrific scene there. Our thanks to you.