"The reason why he did it, it was a prank. There was no intent to harm anyone, per him. It was just a bad choice," said Investigator William Sheehan, Lockport Police Department.
Police say the student used household chemicals and set off the bomb on the second floor. Students were sent home early Monday and 14 received medical treatment. In the end, their tips led to the arrest.
"Students really at the end of the day they do the right thing. They really do step up. They understand it's their environment, it's their place and they want to feel safe and secure," said Supt. Garry Raymond, Lockport High School District 205.
On Wednesday night, the school board held an emergency meeting. There was praise and criticism about how the crisis was handled.
"You locked our children in a building and endangered them even more," parent Cheryl Soucy told school officials.
"I think it was handled very well. I think that some of the other parents have valid reasons for being upset but there were a lot of children here and a lot of things to consider," said Tina Hack, parent.
Police are not finished yet. They're still investigating two threats.
"Now we have time to start investigating the other leads," said Chief Bill Kendziora, Lockport Police.
In the meantime, the teen suspect will be in court on Thursday morning.
On Wednesday, school officials say 94 percent of the students showed up and the schedule will go on as planned with finals and graduation happening by the end of the month.