EVELYN BARNES is picking at her burger and onion rings as we eat lunch at the West Philly Diner.

"Not hungry?" I ask her.

"I have no appetite today," she says. "Maybe it's stress."

Stress must be a constant companion when you're 90 years old, poor and homeless, and you've been driving - heaven help us, Barnes still drives - all over the city looking for an affordable, safe place to lay your weary head.

"I never thought I'd end up this way," says Barnes, who promised to tell me her story over a sandwich. "I don't know what God has in store for me."

It has been four weeks since the back wall of Barnes' North Philly rowhouse collapsed after a rainstorm. She was cooking Sunday dinner when she felt the house shudder so violently, she feared that she'd be buried alive. Thankfully, she, and others in the house, escaped.

But the modest home, where she lived independently since 1983, is uninhabitable. It is owned by her son, who allowed Barnes and her late husband to live there rent-free. She says there is no money for repairs.

"Everything I own was in that house. Well, maybe not anymore," she says, noting grimly that the place has been looted. "I can't believe it's all gone."

For now, Barnes is staying at the Red Cross House at 40th Street and Powelton Avenue, a clean and bright hotel-like facility where a caseworker has been working with her to find permanent housing. It has been an impossible mission.

Barnes' $713 monthly income, her late husband's Social Security benefit, can't cover rent, food and utilities. So she needs a subsidized apartment.

But senior-housing counselors I've spoken with say there is such a shortage of affordable housing for the elderly, Barnes will likely wait two years for an opening.

"I might be gone by then," says Barnes. "Maybe I'm supposed to jump in the river."

Nationally, chronic homelessness has declined by a third over the last decade. But it's growing among the elderly, says Beth Lewis, outreach coordinator at Project HOME. Exact numbers are hard to pin down, but anecdotally, she and other homeless advocates are seeing more gray hairs and feeble bodies on the street.

"Their circumstances vary," she says. "They might have been precariously housed to begin with. Or they have family who can no longer care for them. Our population as a whole is aging, so the homeless are aging, too."

But few are as old as Barnes. The life expectancy among younger homeless is reduced by the factors that contributed to their plight in the first place - addiction, mental illness and lack of jobs, medical care and family help.

While programs exist to help stabilize the mentally ill homeless, there is practically nothing for people like Barnes: alert, elderly men and women who may have worked hard their whole lives but are still poor.

The problem is finally getting federal attention. On Thursday, homeless advocates from across the country are convening in Alexandria, Va., with representatives from Housing and Urban Development, the U.S. Interagency Council on Homelessness and other organizations to address issues that are specific to the elderly.

"The whole 'get them back on their feet' strategy doesn't apply," says Mark Hinderlie, who is convening the conference. He's head of Boston-based Hearth Inc., a nonprofit that seeks to eliminate homelessness among the elderly. "Their health is in decline; they can't work. They need different services.

"Most of us have someone to take us in if we lose our jobs or have a medical catastrophe that wipes us out. But a large number of people are not in that position."

Including Evelyn Barnes. She was a homemaker who raised seven children with her handyman husband, nursed him through a terminal illness and then figured out how to make widowhood work for her on $713 a month.

It was a tightrope she could walk, as long as it never, ever swung. But it did. Now she is in free fall, at age 90.

She says her children, all of them senior citizens, have their own severe financial and medical battles (one is blind, three have cancer, two are struggling in the South). And most of her grandchildren, she says, relied on her for help, before the house fell in.

"You can have a lot of family, but if everyone is sick or poor, they can't help you," she says.

"All my life, I took care of people. Now I need someone to take care of me. I hope God is listening."