Volunteers and city staffers came with pickup trucks, boxes, bubble wrap and black plastic bags — all the necessities used by people who might be packing up a home or office.

But this group arrived in the predawn chill of the next-to-last day of summer to remove 12 white crosses and the piles of teddy bears, silk flowers and other tributes that blanketed a vacant lot across the street from where one of the worst shootings in U.S. history occurred.

“It’s about protecting, preserving and archiving all of these things,” said Aurora History Museum director Jennifer Kuehner, one of the officials in charge of the removal Thursday.

The movers used dry paintbrushes and dishcloths to wipe away thick coats of dirt that had accumulated on the heartfelt mementos placed at the site by friends and strangers from across Colorado and the country.

Since the July 20 shooting — during a sold-out midnight showing of “The Dark Knight Rises” — that left 12 dead and 58 injured, Aurora officials have known that the makeshift memorial on private property would eventually need to be removed as winter approached.

Leading up to the removal — planned for about three weeks — the families of the slain were invited to the site.

“We wanted to give them the opportunity to come down and collect any objects they wanted to keep for themselves before they were boxed,” Kuehner said. “Some families elected to do this; others did not.”

Greg Medek, whose 23-year-old daughter, Micayla, was killed in the shooting, lives a short drive from the memorial site. He recently visited the site and gathered personal notes written in memory of his daughter.

“Some of her friends, and people we don’t know, wrote such touching and kind letters to Micayla,” he said. “That’s stuff we’re going to hold on to forever.”

Kuehner said more than 160 boxes — not including the dozens of plastic bags filled mostly with stuffed animals — were carefully packed and shipped to a warehouse managed by a local charity.

Aurora officials are not disclosing the warehouse’s location.

Items placed near particular crosses were interpreted to “belong” to that victim.

“So we boxed those materials for that person’s family,” Kuehner said, noting that items left in honor of 6-year-old Veronica Moser-Sullivan

were stacked several feet high.

The objects will continue to be cleaned and archived at the warehouse.

Aaron B. Gagné, manager of Aurora’s Neighborhood Services department, said that if family members want to, they can visit the warehouse and pore over items left to honor their loved ones.

“They’ll be able to come in and sit down in a conference room and go through these items,” Gagné said. “There will be ongoing opportunities to do this.”

Some of the items — such as the white crosses bearing the names of the dead and placed at the site July 22 by Greg Zanis, who made a similar tribute for the Columbine massacre — could reappear at a permanent memorial site.

A decision on where a permanent memorial might be built has not been made. Some officials say these discussions won’t begin until Cinemark decides on the future of the theater, Aurora Century 16.

In late August, Aurora officials provided Cinemark with input from an online public survey that asked the community what they wanted to see happen to the theater where 24-year-old James Holmes allegedly opened fire on the crowd.

After Thursday’s four-hour removal process, all that remained on the dusty lot were small scraps of paper and dried flower petals.

Prairie dogs that had ceded the land to the temporary memorial returned, running from burrow to burrow.

For a moment, it seemed as though life had returned to normal.

Kurtis Lee: 303-954-1655, klee@denverpost.com or twitter.com/kurtisalee