The students of Marjory Stoneman Douglas High School returned to class Wednesday, with some looking toward the future and others dreading the memories of the past that would haunt their hallways after a gunman burst onto campus and killed 17 people on Valentine’s Day.

The students, some of whom already returned Sunday for a voluntary orientation, will be attending classes in a revised schedule for a half day. Classes will run for 24 minutes, with only the first period running for 30 minutes. Students will be dismissed by 11:40 a.m.

“It’s gonna be rough. We’re gonna need a lot of help, but we have a lot of help,” senior Milan Hamm told WSVN. “Our principal’s helped, and [Broward School Superintendent Robert] Runcie’s helped us, and just officials and people donating money and just giving back to us has helped us so much.”

Volunteers hang banners around the perimeter of Marjory Stoneman High School in Parkland, Fla., to welcome back students who will be returning to school Wednesday two weeks after the mass shooting that killed 17 students and staff. (Susan Stocker/South Florida Sun-Sentinel via AP)

Students put signs up on Marjory Stoneman Doughlas High School campus.

 (Sun Sentinel 2018)

Runcie also tweeted before classes began: “I pray that today is the beginning of our long and difficult journey from grief, sorrow and anger to a new consciousness of hope, compassion and love. Thank you to our young people for leading the way. Welcome Back!”

Teachers arrived back on campus Monday with one-on-one grief counseling and therapy dogs available to help them cope with the painful memory of the shooting. Counseling and therapy dogs will also be at the campus for students on Wednesday.

Some students showed mixed emotions before returning to school. School officials had initially planned for a Tuesday return, but pushed it to Wednesday. Several believed it was still too early to come back after losing 14 classmates and three members of the faculty and staff.

When asked if she was ready to return to the high school, Ajahne Moore said: “Not really, but I just miss my friends, and one thing I’m thankful for is that I didn’t lose any of my friends.”

“Tomorrow is gonna be a tough day for us, but we’ll grieve and hug and cry it out, and then we’ll march for our lives March 24 and we’ll make it,” another student said. “We’ll get through this.”

A rainbow is seen over the memorial outside of Marjory Stoneman Douglas High School in Parkland Fla., Monday, Feb. 26, 2018. (Joe Cavaretta /South Florida Sun-Sentinel via AP)

A memorial is placed outside Marjory Stoneman Douglas High School.

 (Sun Sentinel 2018)

Teacher Jim Gard, who told Fox News in the wake of the Feb. 14 massacre that gunman Nikolas Cruz was his math student, said he’s “anxious” to return to his school.

“I’m anxious to get back. I’m happy to get back,” Gard told WSVN. ” I think we need to be — it’d be nice for us all to be together.”

Building 12 at the high school — where Cruz opened fire Feb. 14 — will most likely remain closed as the rest of the campus reopens. Runcie previously told the Sun Sentinel there have been “numerous” requests to have the building torn down.

“We’ve received numerous requests from parents, students, community members and local elected officials that they would like the building demolished and some memorial resurrected on the site,” Runcie said.

Runcie is expected to hold an afternoon news conference to give the public an update on the campus return.

Katherine Lam is a breaking and trending news digital producer for Fox News. Follow her on Twitter at @bykatherinelam