SOUTH PORTLAND — When vandals damaged the Little Free Library in her front yard on Summit Street, Bethany Hundt said she was heartbroken.

The cheerful red wooden and glass box was an instant hit after she and her husband, Tim Hundt, put it up. Strangers and neighbors regularly patronized it, taking or leaving a book.

The structure is one of dozens that have sprouted on lawns across the state, part of the national grassroots Little Free Library phenomenon started by a retired Wisconsin educator five years ago.

Hundt said the library managed to bring her neighborhood, which she described as already tight-knit, even closer together.

“Our little library has become a center point for both adults and kids,” she said.

So it was shock when the couple discovered April 11 that someone had smashed in its glass door during the night.

“The worst part was having to explain the entire thing to our 31/2-year-old,” Bethany Hundt said.

While the culprit remains at large, the Hundts say their reaction to the vandalism has turned from shocked to bittersweet.

The idea for the library was hatched more than a year ago when her father, Kurt Kasik of Portsmouth, New Hampshire, was looking for a woodworking project. She stumbled across some building plans for a Little Free Library on the Internet and quickly grew intrigued. She has a degree in literature and teaches an online literature course at York County Community College.

Her father got to work on a prototype.

“It was fun to do,” he said.

The Hundts said they were amazed by the response to the library, tucked away on a dead-end street between Southern Maine Community College and Willard Square.

“People drive over from Portland,” Tim Hundt said.

Patrons have shown up as early as 5 a.m. to browse an ever-changing collection of books – a melange of how-to manuals, travelogues, bodice rippers and the classics. Some children leave little toys. Tourists stop to photograph it.

“I can’t tell you how many times people drive by, stop and get out to look,” said Yvette Pratt, who lives across from the Hundts.

During the past week, the Hundts have been overwhelmed by the neighborhood response to the vandalism. Everyone wanted to know what happened and expressed concern that the vandalism might spell the end of the little library.

“Neighbors talk to us about how much they value the resource,” Bethany Hundt said.

One neighbor flagged down Tim Hundt in his car and handed him a $5 bill toward repairs. Even the South Portland police officer who came by to take their report bemoaned the vandalism.

“He said, ‘This is such a shame. I drive by this all the time,’ ” Bethany Hundt said.

The Hundts said they will definitely keep the little library in business. People continue to use it anyway, despite the broken door. Bethany’s father said he just needs a little time to make the repairs.

And meanwhile, they said, they have learned how a simple, homegrown, free lending library can pull a community together.

“If a little library that takes very little maintenance can do that, what other sorts of community projects could do the same?” Bethany Hundt said.