Minnehaha Academy students, parents, staff and community members gathered Monday to celebrate the completion of the upper school campus two days before the new school year.

About 1,200 people sporting school colors — red, white and black — walked 2 miles from Minnehaha's lower and middle school campus to reclaim their school since a deadly blast upended their lives. They sang and prayed to God in thanks for resurrecting their school and for helping them rise together.

"We have experienced something tragic together," said Donna Harris, the school's president, who was among those injured. "We celebrate the comfort that coming home brings."

It has been two years since a gas explosion tore through the upper campus, injuring nine people and killing two beloved employees: receptionist Ruth Berg, 47, and janitor John F. Carlson, 82.

School officials have been working closely with Mortenson Construction and the design team, the Cuningham Group, to make sure the new campus feels like home again.

The re-imagined space, school officials said, integrates the history and legacy of the century-old building with features of 21st-century teaching and learning.

Black olive trees have been planted under a large skylight just inside the new building.

A memorial plaque marked with scripture sits under the trees.

The orange tiles on one side of the floor in the commons area were salvaged from the school's original 1913 building, among other pieces of architecture that carried over. The new building has multiuse spaces for students to collaborate and connect with staff.

Features of the new building recognize Berg and Carlson.

Two wooden benches sit next to each other in their honor. In a couple of months, school officials will place stained glass windows next to the benches with elements that represent who they were.

Since the explosion, the private Minneapolis school's grades nine through 12 were temporarily housed in a former college campus in Mendota Heights.

Upper School Principal Jason Wenschlag said he hopes students and staff feel at peace being back.

He said four counselors will be on site to help students as they return.

"We want this to be a strong community," he said. "There are a team of people making sure that students transition well into the school and if there are needs that we can help support those needs."

In the first week of August, school officials held separate orientations for students in different grade levels.

During the orientations, school leaders shared their expectations and provided some space for students to get acquainted with the new building.

Trent Chiodo, a 17-year-old incoming senior, had completed his freshman year when the explosion occurred. Wednesday will be the first day of class for Chiodo and his classmates at the new building. They are the only students who attended school at the old building and understand well what this new chapter means.

"I feel unlucky that there was an explosion, but lucky that we have to come back to this place," Chiodo said. "It's exciting."

For others, memories of the Aug. 2, 2017, blast will endure.

History teacher Nathan Johnson has been longing for the conversations he would often have with Carlson, the janitor killed in the blast. The two built a strong friendship that lasted for 15 years, as long as Johnson has been teaching at the school. Carlson, he said, cleaned his whiteboard daily and scrubbed the desks.

"This feeling did not go away the last two years, and I don't think it will here either," he said, choking on his words. "Every time I reach that board at the end of the day, I will think of his care for my classroom and the students."

Art teacher Nate Stromberg, who has been teaching at the school for 17 years, said coming back to the school after the blast is bittersweet.

"To want to celebrate that which so needs to be celebrated feels a little bit strange given that we lost John and Ruth," he said. "And so I have tried to temper my excitement at the same time as I've absolutely just marveled at what they've done here in such a short time. It's miraculous."