MONROE, Conn. -- Buses carrying Sandy Hook Elementary School students rolled into a former middle school campus here, and classes resumed Thursday morning for the first time since a gunman killed 20 children and six adults at the Sandy Hook school in nearby Newtown.

Classes are being held in the former Chalk Hill Middle School, which closed in 2010 but renovated to accommodate the displaced Sandy Hook students. The school has been renamed Sandy Hook Elementary School.

Students and parents, who were invited by school administrators to spend the day at the school, entered a heavily guarded facility beneath picturesque blue skies on a sunny, 10-degree morning with snow covering the grounds.

Police officers from Stratford, Conn., directed traffic at the front entrance, where three police cars were parked. Other police cars were parked at an outpost a short distance down the school's main road.

Police officers, including ones from Bridgeport and Trumbull, Conn., were on the scene, keeping watch, on nearby side roads.

Newtown Superintendent Janet Robinson said officials were doing their best to make the students feel at ease. "We will go to our regular schedule," she said. "We will be doing a normal day."

A new principal, Donna Page, who served as Sandy Hook's principal for more than a decade before retiring in 2010, replaces Dawn Hochsprung, who was among the first victims when a gunman, Adam Lanza, went on a shooting spree Dec. 14.

"I want parents and families enduring the loss of their precious children to know their loved ones are foremost in our hearts and minds as we move forward," Page said in a note on the Sandy Hook school's website. "Your strength and compassion (have) been, and will continue to be, an inspiration to me and countless others as we work to honor the memory of your precious children and our beloved staff."

Robinson said about 500 students attend Sandy Hook, and "the children are so excited to see their teachers" again.

Teams of workers, many of them volunteers, prepared the school with fresh paint and new furniture and even raised bathroom floors so the smaller elementary school students can reach the toilets. The students' desks, backpacks and other belongings that were left behind following the shooting were taken to the new school to make them feel at home.

At one point, there were 80 people cleaning and painting the school to "make it look cheerful and happy," Robinson said. She said she heard laughter from teachers setting up things in a new classroom - an "important" sign that "things were changing."

On Wednesday, the students and their families were welcomed at an open house at their new school. Students received gift boxes with toys inside and shared joyful reunions with teachers.

One father, Vinny Alvarez, took a moment to thank his third-grade daughter's teacher, Courtney Martin, who protected the class from a rampaging gunman by locking her classroom door and keeping the children in a corner.

"Everybody there thanked her in their own way," he said.

Chalk Hill sits in the woods on a quiet road dominated by private homes. Some displayed welcome signs on snow-covered front lawns. Green ribbons adorned mailboxes and fence posts. The ribbons are the color symbolic of Sandy Hook school.

One yard featured a wooden plank that said: "Welcome Sandy Hook Friends Forever In Our Prayers."

Sandy Hook parent Robert Bazuro, who has children in the second and fourth grades, said he was pleased that school was resuming.

"We're very happy the kids are going back and we're very thankful for Monroe for everything they've done for us," Bazuro said.

Numerous police officers on Wednesday guarded the outside of the Monroe school and told reporters to stay away.

"I think right now it has to be the safest school in America," Monroe police Lt. Keith White said.

During the open house, Alvarez said his 8-year-old daughter also got to pick out a stuffed animal to take home from the school library.

"I'm not worried about her going back," he said of his daughter Cynthia. "The fear kind of kicks back in a little bit, but we're very excited for her and we got to see many, many kids today. The atmosphere was very cheerful."

USA Today