Two students were critically injured and a gunman died in a shooting at Great Mills High School in Southern Maryland Tuesday morning as classes began, according to the Saint Mary's County Sheriff's Office.
The gunman who was a student at the school 70 miles south of Washington, D.C., opened fire in a hallway shortly before classes began around 8 a.m., striking a female and male student, said Sheriff Timothy K. Cameron.
Students and staff quickly notified an armed school resource officer, who pursued the shooter and fired a single shot at him, Cameron said at a press conference around 11:30 a.m. The shooter fired back.
The shooter and the two students were rushed to local hospitals in critical condition. The shooter, who was not identified, was pronounced dead at 10:41 a.m., Cameron said.
"On this day, we realised our worst nightmare," Cameron said. "Our children were attacked in a bastion of safety...The notion that it can't happen here is no longer a notion."
It was not immediately clear if the school resource officer's round struck the shooter, Cameron said. The school resource officer was not injured, the sheriff said.
The school was placed on lock down as the situation unfolded.
Cameron said there was "no question" the situation would have been worse if the SRO had not engaged the shooter.
Cameron said they are still investigating a motive and it's unclear whether the shooter knew the students who were shot.
"In my mind, it's a school shooting in the classical sense, but the investigation will have to determine if there was any connection between the shooter and the victims," Cameron said.
Officials with the Bureau of Alcohol, Tobacco, Firearms and Explosives Hyattsville offices were en route to the school, according to a message on Twitter. The FBI's Baltimore office also said they are on the scene, assisting local authorities.
Ronda Neville who lives in Sebastian, Florida, said just after 9 a.m. that she was waiting to hear from her niece who is in the 11th grade at Great Mills. So far she hasn't heard from her or the girl's father, who is her brother-in-law.
"I'm sick over this," she said. Her two sons graduated from Marjory Stoneman Douglas High School in Parkland, Florida, where a former student of the school last month shot and killed 14 classmates and three staff members.
Neville said one of her sons texted her just after 9 a.m. after he heard about the shooting at the Maryland high school. He had gone to Great Mills at one point, she said.
He wrote, "Oh my god. There's a shooting [at Great Mills]," Ronda said she sent a text message to her brother-in-law, the teen's father, and was waiting to hear.
She said, "I just need to know she's okay," of her niece.
Just before 10 a.m., Neville said she got a text from the girl's father saying she had stayed home from school that day. He didn't say why, but said she was safe.
Neville, who said she had just come back from attending funerals for friends, a coach and teachers who were killed in Parkland, was "still stick to my stomach."
Great Mills High School has had recent safety concerns.
Parents at the school became worried after a Feb. 20 Snapchat post that warned students of a possible shooting, according to The Bay Net. com.
In response to the threat, the principal - Jake Heibel - sent a message to parents and told of a report of a student in a hallway mentioning a shooting. He said it had been investigated and "the threat was not substantiated."
The school held a public meeting earlier this month to discuss the threat, he said.
On Tuesday morning, the St. Mary's Sheriff's Office told parents not to go to the school but to report to Leonardtown High School to reunite with their students.
Great Mills High, where the incident occurred, has about 1,600 students.
Maryland Gov. Larry Hogan, R, said Maryland State Police are "in touch with local law enforcement and ready to provide support." He added: "Our prayers are with students, school personnel and first responders."
A spokesman for Hogan said the governor was monitoring the situation and had canceled a planned radio appearance Tuesday morning.
House Minority Whip Steny H. Hoyer, D-Md., whose district includes St. Mary's County, canceled his usual weekly briefing on Capitol Hill and tweeted that his prayers "are with the students, parents, and teachers" at Great Mills.
Hoyer said on CBS9 that it makes him feel "terrible, angry and frustrated."