The scene Monday morning at 509 Main Street in Sanborn was decidedly bittersweet for the onlookers who gathered on nearby sidewalks.

With cellphone cameras recording, they watched the Hartley-Melvin-Sanborn Middle School get reduced to rubble as an excavator methodically tore through the south entrance. The building's demise had been planned for nearly two years, but many in the crowd found the sight tough to absorb.

"It's pretty sad," said Candice Lyman, a 1973 graduate of Sanborn High School. "There are a lot of good memories, but we've got to look out for the kids and their needs now."...