A teenager distraught over a breakup brought a loaded rifle, a hunting knife and bottle rockets to school Thursday, leading almost 2,000 students to evacuate until he surrendered, authorities said.

The 18-year-old senior at Northampton Area Senior High School was taken to a hospital for psychiatric evaluation. He was expected to be charged with two misdemeanors, including bringing a weapon to school, police said.

The student's family declined to speak with reporters.

He was discovered by a teacher as he sat with the weapons in an unused stairwell, smoking and playing music, officials said.

He had used a guitar case to carry the .22-caliber rifle from his home, police said. Some of the other items were found in his backpack.

"He has had a problem with his girlfriend. His girlfriend left him, and he was thinking of ending it all," Police Detective Robert Lindenmoyer said.

Lindenmoyer, the school principal and others talked to the student for 40 minutes before he agreed to surrender, the detective said.

Students were evacuated to the school football field. A search of the building found no other weapons, and officials said classes would resume, but many students said they were going home for the day.

"My mom was hyperventilating on the phone. She said to come home immediately," said sophomore Ellie Berlin, 16. "You don't know what's in there. There could be a bomb."

The school, which does not have metal detectors, is about 50 miles north of Philadelphia.