Branden Colvin Jr. walked the stage at his high school graduation Saturday to rounds of applause and shouts of "we love you."

But one person wasn't there to join in the celebration.

Authorities told Colvin Jr.'s family Saturday afternoon the body of his father, Branden Colvin Sr., had been recovered from the rubble of the partially collapsed apartment building in Davenport, Iowa.

"He's proud of me. He is the reason I was even able to have enough strength to walk across the stage," Colvin Jr., 18, told CNN. "I walked across that stage today knowing my dad is proud of me and will forever be proud of me."

It was a sad resolution to a painful week of waiting for the family of the elder Colvin, who had been missing since the six-story apartment building partially collapsed May 28.

Following the incident, the younger Colvin slept on the pavement near the building site and refused to leave the scene, even as officials warned the rest of the building could come crashing down at any time.

"I haven't slept. I have been out here three days, at night, all night, just waiting for anything," Colvin Jr. told CNN earlier in the week.

Colvin Jr. wasn't sure he would be able to bring himself to attend the graduation ceremony, he told CNN before his father's body was found.

"We had finals this week, Tuesday, and I tried to go to school. As soon as I walked in, I just broke down, and I was just crying," he said. "So, I don't know if I am going to be able to go to my graduation."

He said he longed to hear his father's voice.

"I love how much he talks. Before, it was annoying. But now, I just miss him," he said.

Now he's grappling with the reality of his father being gone.

"I never thought I would lose my dad," he wrote in a Facebook post. "I'll never understand this."

Loved ones still waiting

At least nine survivors were rescued from the building rubble in the days following the collapse. Ryan Hitchcock and Daniel Prien, who, like Colvin Sr., lived in the fallen section of the building, are still unaccounted for, Davenport chief strategy officer Sarah Ott told CNN in an email Sunday.

Officials say they were likely home at the time of the collapse and are asking the public for any information about their whereabouts.

"If you have specific information that can confirm this or indicate otherwise, please call 563-326-6125," Davenport's city government posted on Facebook.

Authorities said Friday search and rescue teams were transitioning from rescue to recovery mode. Crews are now working in 12-hour shifts, around the clock to remove material from the scene, Ott said in a statement Sunday.

The family of Ryan Hitchcock supports the city's plans to carefully take down the rest of the building to prevent further harm, relative Amy Anderson said.

"Ryan wouldn't want anyone else to put their lives at risk," Anderson said at a news conference Tuesday.

"I don't discount that he could be trapped under there miraculously," she said. "But we don't want to see any more families lose their lives or anybody else be injured in trying to remove that rubble and have anything fall."

The daughter of Daniel Prien told CNN she will continue to fight for her father until he is found.

Prien, 60, is a formerly homeless veteran who was placed in the apartment building with the help of a local organization assisting the homeless population, daughter Nancy Prien-Frezza said.

"I do not want them to demolish the building until the missing are found or confirmed to not be there," Prien-Frezza said. "He's a very sweet and loving person. He should not and will not be dismissed because of his situation, so I'll fight to find him and get justice for him."

The city is providing financial assistance for relocation to residential and commercial tenants of the building, as well as nearby buildings affected by the collapse.

Commercial tenants will receive a $25,000 grant to help replace equipment, inventory and start up costs at a new location, while residents of the building will receive a $6,000 grant to help replace lost property and pay deposits on a new place to live. People from adjacent buildings will be granted smaller amounts.