Nearly four months after the Parkland, Florida, community was devastated by a deadly school shooting, seniors at Marjory Stoneman Douglas High School gathered on Sunday to receive their diplomas.

The community anticipated a bittersweet occasion, as students — dressed in maroon caps and gowns — and teachers planned to honor the 17 students and faculty killed, including four seniors who would have graduated today.

On Sunday morning, Jeff Foster, the AP Government teacher and grand marshal of the graduation, took to Twitter to let his students know they had his support.

“Today is going to be emotional,” he wrote. “Just know that I will always be there for you. I love you.”

Ahead of the ceremony at the BB&T Center in Sunrise, Florida, MSD teacher Darren Levine told CNN the mood was somber.

“There’s definitely a solemn feel mixed with joy, which is weird,” Levine said.

During the ceremony, the names of each of the deceased seniors were called, and their family members and close friends came forward to accept their diplomas.

The family of Joaquin Oliver, one of the students killed when a gunman stormed the school on February 14, planned to attend the ceremony. Joaquin’s parents received his diploma in his place.

It was an emotional scene, according to Levine. Joaquin’s father, Manuel Oliver, ran up the aisle between the graduating students to loud cheers and applause as the crowd gave him a standing ovation. Meanwhile, his mother wore a yellow shirt that read, “This should be my son.”

Hunter Pollack, brother of victim Meadow Pollack, received his sister’s diploma in her stead.

Levine told CNN some attendees shed tears as students, holding hands, sang “Shine,” a song written by MSD students in the aftermath of the shooting.

Another teacher told CNN the senior class president, Julia Cordover, gave an emotional speech encouraging classmates to use their votes to change the world.

The ceremony also honored the three faculty members killed in the shooting. Representatives for teacher Scott Beigel, Coach Aaron Feis and athletic director Chris Hixon each accepted a statue of an eagle in their honor.

A surprise guest

School faculty had teased the fact that a special guest would speak at the ceremony, and students and their families were eventually surprised by Jimmy Fallon, host of the “Tonight Show.” Like the students, Fallon wore a sash that read, “MSD Strong.”

“Today you’re graduating from high school,” he said, according to videos posted to social media and shared with CNN. “You should feel incredibly proud of yourselves. That doesn’t mean you should rest on your laurels — or your yannys.”

Fallon also thanked the class for their “courage” and “bravery.”

Some attendees called attention to gun violence

Some of the students decorated the slates of their caps with homages to their lost friends.

One of Meadow’s best friends, Carley Ogozaly, decorated her cap with a picture of Meadow and the words, “We are still in this together.”

Other students like David Hogg — who has become a prominent voice in the shooting’s aftermath — used their caps to make a political statement.

He shared a photo of his cap, painted orange, with a price tag that read “$1.05” on Twitter.

“Thanks for the tassel @marcorubio,” Hogg wrote.

Student activists wore similar price tags at the March for Our Lives rally in March as a dig at Florida Sen. Marco Rubio and the National Rifle Association. The figure is meant to represent how much each student in Florida is worth to Rubio, based on how much money he received from the NRA.

Students weren’t the only ones making a statement. Some teachers used orange lipstick to draw strips beneath their eyes as part of a movement called the Lipstick Lobby. The shade of lipstick was meant to draw attention to the issue of gun violence.

The mother of Carmen Schentrup, another senior killed in the shooting, wore orange lipstick in the movement’s advertising campaign.

Since the shooting, MSD students have led a national conversation about gun violence through various protests, like school walkouts and the March for Our Lives, which saw massive crowds turn out in Washington and around the country.