A crumbling, half-empty apartment complex in southwest Houston is a mere speck in the vast sweep of Hurricane Harvey's path of destruction. If we zoom in for a closer look, though, the tenants of the Rockport Apartments can tell us a story. It's not a pleasant one.

"My brother is a little bit sick," said 11-year-old Stephanie Plancarte, who sat on a stairway in a courtyard on Thursday with 5-month-old Alexander curled in her lap. She explained that the baby had trouble breathing after spending a night in a flood-damaged bedroom where mold was creeping up the wall.

"Now," Stephanie said, "we're sleeping in the living room."

Why would a family choose to stay in a wet, mold-infested apartment?

Many of the tenants of the Rockport Apartments, like those in other aging, poorly maintained developments across the Houston area, have limited options even under normal circumstances. Harvey's floods narrowed those choices even further.

Poor people assemble their limited resources - one functioning car in a family with three working adults, a school within walking distance for the kids, a nearby relative who can baby-sit the youngest - into a system that sort of works most of the time. Any disruption, though, can topple the whole structure.

That's why one family I met at the Rockport Apartments, the Segovias, stayed in their apartment despite the mold on the walls. Available shelters are too far from their jobs, and they can't afford to miss work because management provided only a brief grace period - Thursday was the deadline - before late fees would be added to their monthly rent of $820.

The first day late, $55. Each day after that, $35.

The six family members share a two-bedroom apartment. One child sleeps in a hammock in the living room.

Erlin Segovia, standing in the kitchen with a child balanced on one hip, acknowledged she was worried about the effects of the mold on her family's health: "It's very bad," she said. But all the other choices seemed worse.

Herminia Patino faced a similar dilemma. At the height of Harvey's rainfall, water in her apartment was hip-high. She and her daughter Jolene, 9, stayed in the apartment for one night, then moved in with a friend in another unit at the Rockport, located near U.S. 59 and Bissonnet.

On Thursday, Patino unlocked her apartment door so that Chronicle photographer Elizabeth Conley, community organizer Alain Cisneros of FIEL Houston and I could see the damage. Cisneros is trying to help the tenants at the Rockport.

The place was a ruin.

A powerful stench met us as soon as we stepped in. A rug and the walls were still wet to the touch. The walls and furniture were coated with black mold.

Patino, too, is reluctant to relocate because Jolene just enrolled in a nearby elementary school. Patino has no car.

Because her apartment was so devastated, she said, the manager agreed to forgo this month's rent. She's not sure what she'll do; she can't stay with her friend indefinitely.

It's unclear when, or if, the flooded units at the Rockport will be repaired. Some 250 units, about half of those in the development, were destroyed by a 2015 tornado; most or all of them still sit vacant and boarded-up.

I was unable to reach the development's managers or owners Thursday. A man in the leasing office, who identified himself only as David, wouldn't answer questions. An email I sent to an address provided didn't yield a response.

Many tenants at the Rockport are immigrants living in the United States illegally, a circumstance that further limits their choices. As Chronicle reporter Lomi Kriel reported recently, tougher immigration measures at the state and federal level have made these immigrants reluctant to seek government assistance. Fear of deportation also makes them less likely to complain about heavy-handed practices by their landlords.

"These are the most vulnerable, the most exploited people after any natural disaster," said John Henneberger, co-director of the Texas Low-Income Housing Information Service.

Stronger city enforcement of housing codes - a perennial problem in Houston - would benefit residents of rundown developments like the Rockport, said Henneberger. And tenants themselves, he said, need to organize to protect their interests.

"It is incredible to me that the fourth-largest city in the country has no tenants' movement," Henneberger said. "The Austin Tenants' Council would be all over this."

In the short term, the government and nonprofit agencies working so diligently to help the region recover from Harvey might give some thought to the plight of a few people in moldy apartments in southwest Houston. Right now, all of their choices are bad.