A gunman opened fire at a Texas high school Friday, which ended in a tragic unexplainable killing of at least 10 people, most of them students, who were also targeted by placing explosive devices in and around the building, police said.

Nine students and one adult were killed in the shooting at Santa Fe High School in Santa Fe, Texas, that erupted before classes began, a law enforcement official not authorized to comment publicly told USA TODAY. The suspect was later taken into custody.

The shooting was the worst since Feb. 14, when a former student killed 17 people at a Florida high school and ignited a national debate on gun control.

The official said multiple pipe-bomb-type explosives were recovered at the school, but investigators were still going through the building.

‘The suspect was identified as Dimitrios Pagourtzis, 17, according to a second official briefed on the investigation but not authorized to comment publicly. It’s not USA TODAY’s policy to identify minors charged with crimes. Due to the magnitude of the event and the fact the suspect could be charged as an adult, USA TODAY has decided to identify the suspect.”