Classes resumed at Danvers High School two days after student Philip Chism, 14, was charged with murder in the death of Colleen Ritzer, a 24-year-old math teacher. School had been canceled the previous two days.
On Friday, the U.S. flag outside the school flew at half-staff, and the pink ribbons hung from a row of six trees in front of the building.
An electronic sign displayed a tweet that Ritzer posted this summer: "No matter what happens in life, be good to people. Being good to people is a wonderful legacy to leave behind."
"RIP Miss Ritzer. Gone, not forgotten," was written in the school colors of blue and white on the windows of a pickup truck in the student parking lot.
A police officer stood outside a cruiser in front of the school, part of the extra security. Side doors were to be locked for the next few days, and counselors would be on hand, officials told 800 parents at a meeting Thursday night.
Student Dylan Fitch, who was in one of Ritzer's classes, said on Friday morning that he thought the return would be "awkward."
"We can get through it, but it's really not going to be the same," he said.
Rabih Chaghouri, whose daughter is a freshman, said he's confident the school is safe. "This could happen in any neighborhood, any street, anywhere. You never know what goes on in people's heads."
Authorities have offered no clues on Chism's alleged motive. They also would not say how Ritzer was killed.
Tuesday's school day ended for both Chism and Ritzer in her last-period Algebra I class, where she noticed him drawing in a notebook rather than taking notes, said Chism's classmate Rania Rhaddaoui, who sat two seats from him. Ritzer asked Chism to stay after class, Rhaddaoui said, but she didn't know why.
Ritzer never returned home. Blood in a second-floor school bathroom helped lead investigators to her body, which was dumped in the woods behind the school in this close-knit community about 20 miles north of Boston.
The second-floor bathroom at the school would be closed indefinitely, Danvers police chief Neil Ouellette said.
Authorities believe Ritzer was killed after school ended at about 2 p.m., but they have not released a specific time.
Police picked up Chism early Wednesday, as he walked along Route 1 in neighboring Topsfield. Chism appeared briefly in court Wednesday for arraignment on a murder charge and was ordered held without bail.
Chism had moved to Massachusetts from Tennessee before the start of the school and excelled the junior varsity soccer team.
Caio Silva, a Danvers High School senior and varsity soccer player, said he knew both Chism and Ritzer. He said he and his teammates are helping each other.
"A lot of the guys are really shocked, a lot of guys are down, really upset," he said.
"It's just really sad," he said. "A lady that was really sweet and a kid who was really sweet. It just doesn't really match up."
Associated Press writers Denise Lavoie in Boston and Rodrique Ngowi in Danvers contributed to this report.