PARKLAND, Florida — Seventeen people were killed in a mass shooting in Parkland, Florida by an suspected ex-student of the high school on Wednesday as students were preparing for dismissal at the end of the day, Broward County Sheriff Scott Israel said.

An additional 15 people were hospitalized, CNN reported.

The incident at Marjory Stoneman Douglas High School in Parkland, Florida began around 2:30 p.m. ET. Nikolas Cruz was taken into custody off-campus about an hour after the shooting. The suspect was a former student of the school, according to Israel. Cruz is said to be a current student at another Broward County high school.

The Broward County Sheriff confirmed Wednesday afternoon that the shooter is in custody.

Israel said that the shooting began outside of the school, and then Cruz allegedly moved inside of the school. Twelve were killed inside the school, two were killed outside of the school and one was found dead on a roadway, Israel said. Two other were pronounced dead at a hospital.

Israel said that Cruz had an AR-15 type weapon, and countless magazines in his possession.

MORE: Photos from the scene

According to WTVJ, someone pulled the fire alarm at the high school before opening fire on students.

A local fire chief told the Miami Herald there was at least one person killed. Broward County has classified it as a "Level 3" casualty incident, meaning at least 20 people are wounded.

Much of the area around the school was blocked off to the public. It took some time for students to be reunited with their parents.

President Donald Trump has been briefed on the shooting. He tweeted his condolences to the families of the victims on Wednesday afternoon.

Florida Attorney General Pam Bondi said that the state would pay for funeral expenses for the families of the deceased.

My prayers and condolences to the families of the victims of the terrible Florida shooting. No child, teacher or anyone else should ever feel unsafe in an American school. — Donald J. Trump (@realDonaldTrump) February 14, 2018

Just spoke to Governor Rick Scott. We are working closely with law enforcement on the terrible Florida school shooting. — Donald J. Trump (@realDonaldTrump) February 14, 2018

The daily White House press briefing originally scheduled for 4:30 p.m. was canceled due to the incident.

Stoneman Douglas High School has more than 3,000 students in grades 9-12. Parkland is located between West Palm Beach an Fort Lauderdale, near Coral Springs.