Tragedy struck Perry Hall High School on the first day of classes Monday after a student at the Baltimore school was shot and seriously wounded and a suspect was arrested.

A suspect in the Perry Hall shooting was taken into custody after allegedly opening fire in the school's cafeteria Monday morning, hitting a student who is now in critical condition, the Baltimore Sun reported.

Perry Hall High School junior Miranda Wienecke said she saw the alleged shooter with a black object that she realized was a gun.

"I saw people getting under the table," Wienecke told the Sun. "Then I saw people running. We heard this huge boom, then there was another one, everything happened very fast."

The 17-year-old student who was shot was not identified. He is listed in critical condition.

In a statement, Maryland Gov. Martin O'Malley called the shooting "a senseless act of violence."

"I'd like to thank the teachers and administrators for their courageous and life-saving actions," the governor said. "At this time, our thoughts and prayers are with the injured student and his family."

After the student was shot around 10:45 a.m. ET, teachers tackled the suspect shortly after the gun went off.

"I saw the kid shooting then the teacher tackled him and the first row started running, then the second run, then everyone was running," student Gerald Roman told CBS Baltimore.

A lockdown of Perry Hall was instituted following the shooting. Some students said there was mass chaos in the aftermath of the incident.

"It sounded like a fight against the locker with all the banging.  I heard screaming and the teachers told everybody to stay calm... it was crazy," student Justin Spencer told CBS Baltimore. "When all the teachers started running to the classrooms and locking the doors, and then on the speaker we heard the teachers saying 'Lockdown. Lockdown. This is not a drill. We need everyone to stay in the classrooms.'"

The male student who was shot was taken to Shock Trauama via helicopter and was listed in critical condition as of 1 p.m., according to WBAL.

Following the shooting, Perry Hall students were evacuated to the fields behind Perry Hall Middle School, with buses picking them up and sending them home, the station reported.

As students and parents came to grips with the shooting, a rumor surfaced that there was a threatening Facebook post online about the school that read, "First Day of School, Last Day of Life," but CBS Baltimore said the claim could not be substantiated

The Perry Hall shooting led the high school to trend on Twitter. Students said the incident is not indicative of the environment at the Baltimore school.

"Perry Hall isn't a bad school. This could happen anywhere," said @GoTo_MD.

Others expressed sadness and sent out their prayers to those affected by the school shooting.

"So sad and scary to hear about what happened at Perry Hall," said @MikeLovesTori.  
It seems like school shootings are occurring more frequently. This is not good."

"Praying for the families of Perry Hall, but for the love of God, this mess has got to stop," said @AshleighxBabyyy.

"Praying for the parents, students, & teachers today @ Perry Hall High School," said Matt Krimm. "Sad to hear about the shooting there today. Heartbreaking."