The old man with the bowed back begging for change from his wheelchair found few customers at the Fulton Street Mall in downtown Fresno.

Anyone could see he needed help. On a cool day, he was stationed outside one of the discount children's clothing stores, wearing torn sheets like a toga, his gray stick legs exposed, flies hovering around his lap. But there were so few passersby to solicit, so few shoppers this day as on any given day on one of the main thoroughfares in Fresno (population 456,000), that the old man would starve if he did not know to head to one of the soup kitchens several blocks from the mall.

At the soup kitchens, the curious emptiness of downtown Fresno is reversed. The lines for meals are packed with old people, young couples, extended families, blacks, whites, Latinos. Fresno, the largest city in California's expansive Central Valley, may have gleaming new office buildings and an award-winning baseball stadium, but it remains a poor city overwhelmed by need. A short hop from City Hall, people live in slum buildings where roaches crawl in tenants' ears, the black mold looks like wallpaper and families split the rent by sleeping in walk-in closets, laundry rooms and bathtubs.

This city at the heart of the richest farmland in the world has been poor for so long, no one can remember it otherwise. Last month, when the Brookings Institution issued a report that said a higher proportion of poor people in Fresno lived in areas of concentrated poverty than in any other major city in the country -- pre-Katrina New Orleans was number two -- no one here was surprised. "My goodness, that's why I ran," said Alan Autry, who became mayor in 2000. "I called it 'A Tale of Two Cities.' "

Nonetheless, the Brookings study has spurred a call to arms here. Using 2000 Census data, it found that 43.5 percent of Fresno's poor live in extremely poor neighborhoods (where more than 40 percent of the residents live below the federal poverty line -- $17,600 a year for a family of four).

While city and private organizations were already working on attracting more jobs and improving living conditions, poverty is now topic number one in and out of City Hall. On Oct. 25, the Fresno City Council unanimously approved the creation of a "poverty task force," its first, to tackle what the Brookings report said are the most pressing problems confronting high concentrations of poverty -- lack of quality education and health care, job training, substandard housing and crime.

"What we are going to do is involve all scales of government -- that's the only way this is going to work," said Cynthia Sterling, the council member who called for the task force and whose district includes the two poorest sections of the city, downtown and south Fresno.

Officials and community leaders say the city has made strides in the past five years. Unemployment is down from 15 percent to 7.3 percent, the lowest in 20 years. The crime rate has dropped, and $45 million is being invested in creating and repairing infrastructure in poor neighborhoods.

But fighting poverty in Fresno (which ranks 16th among the nation's largest cities in terms of its overall poverty rate) may prove more than daunting. Unlike the other cities the Brookings report found with the most concentrated poverty -- New Orleans, Louisville, Miami and Atlanta -- Fresno is still, in many ways, a farm town. The city's dominant industry, agriculture, depends on a cheap, seasonal work force that keeps renewing itself as successive new waves of immigrants arrive.

The city's high dropout rate leaves a workforce ill-prepared for higher-paying jobs that Fresno is trying to attract. Not least, a housing boom in the past few years has exacerbated the city's concentrated poverty. Real estate has skyrocketed, leaving south Fresno as the last refuge for poorer residents forced to move because of rising rents elsewhere.

With all the new housing, "no affordable units were built," said Chris Schneider, the executive director of Central California Legal Services, whose clients are the Central Valley's poorest residents.

A drive through south Fresno found streets with wilted, squat wooden and concrete houses, a handful of prostitutes standing dejectedly on corners, huddles of young men standing outside a weedy lot drinking beer and mothers with children, but few children playing on the streets. North Fresno appeared like a suburb, with gated communities, shopping centers and traffic heavy with late-model SUVs.

The mayor agreed that the lack of affordable housing and decent jobs are major issues confronting the city. But, he said, illegal immigration is perhaps the greatest challenge to Fresno. "We're going to have to secure the border, he said, "reform the illegal immigration system and create a plan that addresses the 4.5 million immigrants in California that doesn't involve amnesty or sending them back."

Autry said that although officials have no idea how many illegal immigrants live in Fresno (the city is about 45 percent Latino, mostly Mexican, with a rising number of Hmong refugees), 20 percent of the people in the county jails are illegal immigrants. About one quarter of emergency room visits are from illegal immigrants and the vast majority of the tenants in the worst housing in the worst neighborhoods are immigrants, presumably including illegal immigrants.

"If we don't have a policy that allows an immigrant to come across with their dignity and their respect as well as their work ethic, we're going to pay an awful price," Autry said. "We already are." He added that Fresno is organizing a summit, to be held next month, where mayors from cities with high populations of undocumented immigrants will devise a plan to tackle the problems they are facing.

But illegal immigration, the mayor acknowledged, cannot be blamed for all of Fresno's woes. As those fleeing the skyrocketing housing prices in Southern California and the San Francisco Bay area have converged here in the past three years, land and housing prices have increased by nearly 60 percent, according to the city's housing department, making the dream of homeownership for the working class more distant. Meanwhile, rents have increased by nearly 15 percent.

Developers have swooped in, renovated some of Fresno's deteriorated apartment buildings and then raised the rents, making them unaffordable to low-income residents. The poorer tenants must find cheaper housing, most of it in south Fresno, further concentrating the poverty there. In south Fresno, old wooden buildings are packed with new and longtime immigrants afraid to complain about egregious conditions, including roaches, broken toilets and mold. The cheapest three-bedroom houses rent for $500 a month, but they are nearly uninhabitable.

"The people are afraid to speak up," said Christina Miranda, a tenant organizer who spends her days trying to help poor residents learn and exercise their rights. "Some of the farm workers are Mixtec, from Oaxaca -- they don't even speak Spanish. They speak a dialect. The Cambodians are very closed off as well. The situation is perfect for a slumlord."

Rising rents are sending full-time workers to soup kitchens. Poverello House estimates that 70 percent of the average of 1,200 meals it serves each day are to people with minimum-wage jobs who cannot get by without help.

The Fresno Rescue Mission, which operates the largest homeless shelter in the region, providing 300 beds a night, has found the lines longer at its soup kitchen and the demand for shelter greater than ever. About one quarter of the people who now come to the mission for meals work full time but cannot pay all their bills. "Apartments that were $400 two years ago are now $800 to $900 a month," said the Rev. Larry Arce, director of the mission.

Sterling, the council member starting the poverty task force, said that its first job will be a "thorough needs assessment" in Fresno, starting with her district, which has the highest rate of crime and gang activity and the lowest graduation rate. "This is just a blessed opportunity we have now," she said, referring to how the Brookings report put poverty on the political agenda.

A neighbor's dog and a doll keep Summer Speckman, 5, company as she sits on the sidewalk out front of her family's dilapidated apartment in southeast Fresno. A Brookings Institution study found that 43.5 percent of Fresno's poor live in extremely poor neighborhoods.