EAST LANSING, Mich. (WOOD) — Michigan State University police and the Federal Bureau of Investigation are working to return hundreds of items left behind after a shooter killed three students Monday night and seriously injured five others.

Students and staff have been returning to the MSU Union throughout the afternoon. Student Connor Dunn came back to pick up what he left behind when a gunman started firing.

“Everybody got up. Started running. I personally went out the north door of the Union,” he recounted.

He dropped his phone as he ran for his life.

“Ended up getting a hold of my friends and family. They had all been, like, tracking my location after they heard the shooter was in the Union and my location still told everybody I was in the Union. I think that frightened a lot of people,” Dunn said.

He returned to the building today with his father.

“It was hard because I remember. I almost relived the whole thing,” said Dunn.

“I remember when I went to my stuff being in the exact same spot that I was sitting when the first shots went off. I do remember kind of looking over toward the kitchen area from where I was only maybe 20 feet from the kitchen. I remember looking over there and kind of remembering exactly what had happened and the path that I took to get out of the building,” he said.

Dunn remembered hearing the first shot not knowing what was going on.

“I assumed that somebody had dropped a tray just based off the sound and where the shot sounded like it came from, then the second and third shot came and that’s when I realized something wasn’t right and I needed to get out, get out of the building.”

MSU Police worked with FBI victims specialists Wednesday afternoon, guiding students as they returned inside.

“There’s a lot of items in there and it’s a complicated process to get everything together, bring it out and then try to give it to them at another location,” said Jim Tarasca, special agent in charge with FBI Michigan.

Therapy dogs were brought in to comfort students who went inside. Student Enzo Sugameli said he couldn’t find his phone, which was lost as he rushed to safety.

“I was able to meet up with some of the people I know and we just ran west afterwards,” said student Enzo Sugameli.

He said he was not concerned about coming back and just really wanted his phone to respond to friends who were reaching out. He did not end up finding it.

“When I came back into the building, I was not really too disturbed. I actually managed to see some of the people that I saw the night that I haven’t been able to see for about two days now,” he said.

Tuesday, the FBI tweeted a request for people to submit any photos or videos they may have of the shooting. A web page is open and available to upload files along with your name and contact information.

Students, faculty and staff who had items left in Berkey Hall will be able to get their things at 10 a.m. Thursday at the east entrance. FBI employees and victim specialists will also be there to help and check in students, according to a news release.

MSU police asked that anyone picking up belongings bring a form of identification to the check in, such as student ID’s or driver’s licenses. Recognizing that people may have left their ID’s in the building, MSU police wrote in a release, “Please do the best you can. No one will be turned away without further assistance.”

Mental health professionals are available on site. The toll of what happened is having an impact that students are trying to overcome.

“I have not slept more than 10 hours in the past 48 hours and I’m hoping to get more as time passes,” said Sugameli.

Returning to class Monday is something Dunn is still trying to process.

“I think this down period that we’re having, that MSU has provided us, is definitely going to help a bit but I think I’ll be alright because I have a great support system — my family, my friends. But I can’t say the same for everybody else because I know some people had it a lot harder than I did.”

If students or staff are not comfortable coming back to the Union or Berkey Hall, the FBI will make other arrangements.