From the opening day in the early 1970s, people loved living in the high-rise condo in Edina. In fact, they liked it so much that many never left.

Today, half of the residents are senior citizens. Last spring, someone tried to flush an adult diaper down a toilet. The overflow of water caused so much damage to walls and ceilings in units below that residents had to move out for repairs.

Thousands of high-rise condominium and co-op units have been built in the Twin Cities in recent years, many of them filled by empty nesters hoping to live out their lives in maintenance-free comfort. But as those people age -- the number of Minnesota residents 65 and older is expected to outnumber children 2 to 1 in the next 15 years -- the problems of growing old while living stacked on top of each other will multiply.

What happens when someone with dementia forgets to get dressed and wanders through the halls naked, or can't remember which doorway is the right one? When someone falls, are neighbors supposed to help? Can people be forced to move if they pour an entire box of soap in a dishwasher, filling their condo with an ocean of bubbles?

It's an emotional and legal minefield for neighbors, families and building managers who struggle to balance the rights of individuals with those of the community. While seniors who live in apartments often can be made to leave, as a condition of their lease, if their health begins to fail, people who live in condos or co-ops have the same property rights as someone who owns a house. It's nearly impossible to evict people without proving that they are a danger to other residents or to the building as a whole.

"It's all very touchy; you really have to walk the tightrope," said Ross Peterson, president of Multiventure Properties, which manages the Edina high-rise where the toilet overflowed. "Other residents don't understand that you can't just evict people. It's quite an involved process. And sometimes [people] won't recognize that they need help."This is no different than our neighborhoods," said Alice Finley, a condo manager for Ebenezer Management Services, which specializes in senior housing. "People love their communities and don't want to leave, and communities struggle . ...

"It's sad. It's going to get worse as we age in place. Where are we moving? Condos and townhouses."

No forced moves

At 7500 York Cooperative in Edina, the average age of the roughly 420 residents is 85. When the nine-story building was erected in the late 1970s, it was the nation's first senior housing cooperative. The building has had a waiting list to get in ever since.

The co-op's mission statement says it provides "a safe, healthy, and pleasant home for its members to enjoy an active, independent lifestyle." When Esther Schmidt, an 89-year-old member of the co-op's board of directors, gives tours to prospective buyers, she's seen some bristle at the sight of a resident with a walker or a wheelchair.

"I don't want to live in a nursing home," one man huffed during a tour. When the grumbling continued, Schmidt diplomatically pointed out that, someday, he might need that kind of help.

Frailty can be a sensitive topic. The co-op has had people flush objects down toilets or let sinks overflow. The board decided to install plastic flippers outside each door that flop down when the door is opened. Staff will check on residents who haven't opened their door by midmorning. But some residents have objected.

"Some people are very independent and they don't want anyone checking on them," Schmidt said.

Changing laws have curbed the co-op's control over who lives there. Once, new residents had to have a physical that showed they were able to live independently. New federal fair housing and disability rights laws changed that. Until a few years ago, the board of directors could ask residents who seemed to be a danger to themselves to undergo a geriatric assessment. If they refused, the board could revoke their membership, forcing them to move.

Now that's against federal regulation, too. The co-op can seek an outside assessment only if someone is deemed a risk to other residents or to the building at large.

Accidents happen

Finley, who has a degree in gerontology, said "dementia does not guarantee that people are going to cause a problem" in a building. Perfectly healthy people have been known to flush dentures and hairbrushes down the toilet. Kids clog toilets with toys all the time, and more than one harried mom has absent-mindedly dumped a baby diaper in a toilet bowl.

But if people's health begins to fail and creates repeated problems, managers need to document the events, Finley said. Adult children or guardians should be involved and need to know that building caretakers and fellow residents are not responsible for helping to care for aging parents.