The armed student, who shot two other students at Great Mills High School in United States' Maryland on Tuesday has died.
"I pulled over and nearly puked", said Adlai Traver, 18, who attended Great Mills in his freshman and sophomore years and knew all three kids involved in the shooting.
The injured girl was hospitalized in critical condition and the injured boy was hospitalized in stable condition, authorities said.
St. Mary's County Public Schools Superintendent Dr. Scott Smith said "this is our worst fear". A gun was taken to school, and discharged, and [in this case] somebody died and two people were wounded.
Cameron said the security officer fired a shot at Rollins, but it was not immediately clear if the officer struck the gunman or whether he had committed suicide. Regardless, an investigation is underway.
In a letter Tuesday night, the principal of Great Mills wrote school will resume April 2. Threats against schools have proliferated as well, and Great Mills High has not been immune.
Willey's family requested prayers and privacy. Those looking to reach out are encouraged to make donations to the link below. But it could have dragged on longer and proven deadlier were it not for the rapid response of a school resource officer.
One of the shooter's friends, 14-year-old Jordan Hutchinson, and his mother dropped off a condolence card at the Rollins home. "I don't want to go through it again".
The officer, Deputy First Class Blaine Gaskill, a six-year veteran with SWAT team training working his first year inside the high school, responded quickly, Cameron said.
Tracey Harms's son is a sophomore at Great Mills. The shooting is the latest case highlighting the links between gun violence and domestic violence.
Rollins was confronted by the school resource officer, they exchanged gunfire, and Rollins was later pronounced dead at a local hospital.
"School is supposed to be a place of fun and joy and learning, but we are seeing all too often that they have become a place of anxiety for some students".
A sheriff's spokeswoman says injuries have been reported after a shooting at a high school in southern Maryland.
The county sheriff said deputies are on the scene and that parents or guardians should stay away, going instead to Leonardtown High School to reunite with Great Mills students there. "So if he would have been a couple minutes earlier, he would have been right in the same area", she said.
Davis' first tweet about the shooting quickly prompted tweets of encouragement from Florida students who survived a February 14 massacre at Marjory Stoneman Douglas High School, where 17 students and staff were shot dead.
Education Secretary Betsy DeVos called the incident at Great Mills a "horrifying situation", and said her agency stands ready to help.
Agents from the federal Bureau of Alcohol, Tobacco, Firearms and Explosives have also been sent to the school.
The survivors are organizing a national demonstration for gun control laws on March 24 called March for Our Lives.
Republican Gov. Larry Hogan, meanwhile, accused the Democrat-led Legislature of failing to take action on "one of the most aggressive school safety plans in the country".