They stopped at various points along 100 Hall to peer into glass cases, at plaques, awards, trophies, citations, perhaps with their names or the names of friends living or dead on them.

Some laughed at the dates, at just how absurdly long ago they had accomplished this in music or won that in athletics, or in other fields.

And everywhere, on sunny walkways between buildings, in classrooms, in the music building, old friends met, did double takes, recognized faces and embraced.

Such was last Saturday’s walk-through of Auburn High School, a last chance for alumni to look the school over before the 64-year-old building goes down in dust and splinters to make way for a parking lot for the new one on East Main Street.

The high school’s $110 million successor opens in September.

“I’m sad to see it go,” Tamera Reisenauer, class of ’99, said of the old building. “But at the same time, I’m glad to see it go and to progress to a new version. I had a lot of great memories here. But you know, we’re talking about structural integrity, and we’ve got to make sure everybody’s safe,”

Suzi Reynolds (nee Blattner) relived classes in the biology lab.

“I was nervous about taking biology because I had heard they cut open frogs and dissected them. But when I actually had to do it, it was a fascinating experience, and I just walked away from it going, ‘I did not expect that.’ But, oh my God, the smell from that formaldehyde!”

Elizabeth McClain, class of ’98, recalled ruminating over “boyfriend trouble” with friends at spots known only to them in various hallways, and about trying to find classrooms on the first day of school.

“Little sparks of memory,” McLain said.

One man laughed about a friend who once snuck into the women’s restroom in the music building and pasted in the stall a positive note about himself. And how deflated the friend was two weeks later to read sharp insults about himself.

Another man recalled watching through a window in 1964 when a powerful earthquake struck the region, and the surreal experience of seeing seismic waves ripple along Troy Field.

More than one former student making his or her way to the old gym, called “The Pit” was heard to say, “Yep, same old smell.”

Former band mates, finding themselves together in the music building, picked up instruments and, to cheers and hollers, launched into an impromptu version of the Trojan Fight Song.

At a table one could buy message bricks to be installed at the entrance to the Auburn Performing Arts Center. One to two lines will set you back $75, three lines, $85.

Auburn High School Principal Richard Zimmerman won’t miss the old building or its ancient boilers or ancient anything else — at all.

And no, he laughed, he won’t be throwing himself in front of heavy demolition equipment or chaining himself to the building to stop it.

What’s next is that toward the end of June, he said, a company will come in and remove all the furnishings that aren’t attached to the building. Then maintenance workers will clean everything out of the main building they need.

On July 1, the demolition contractor gets possession of the main building.

“That’s when they start the asbestos abatement in the building, and we don’t know how long that’s going to take,” Zimmerman said. “Once that’s completed, we start demolition of the building.”

Because nobody knows how long the asbestos abatement will take, however, there is no firm demolition date.

Actually, Zimmerman noted, the first to be demolished will be the metal shop, wood shop, and electronics and horticulture area.

“We’re actually starting to move their equipment on (Monday) because we need to get them out of there. The reason we have to do that so quickly is that the bus loop for the new school goes right through there,” Zimmerman said.

“We’re closing the gym up the last week of school. Starting on the 16th, building maintenance is going to put plywood down in there, and we are going to be moving everything that’s going to the new school into the gym, and it’s going to be there for the summer, and it will be secured,” Zimmerman said.

The PAC closes at the end of June and will remain closed for a year of extensive remodeling.