The magnitude of the disaster hit Peter Brown on Thursday.

On the Allentown native's first full day helping with Red Cross efforts in Houston, he watched an older man struggle to maneuver himself onto a cot inside a shelter in Houston's Third Ward.

"I kept thinking to myself, 'This man probably doesn't have a place to go back to,'" Brown said Friday morning. "You feel good you're doing some basic things to help, but you start to worry about what these people's lives are going to be like in three or four months."

On Wednesday night, Brown, 55, director of the Lehigh Valley-Bucks Chapter of the American Red Cross, arrived in the city for his first disaster deployment.

The father of three volunteered Sunday after he and his wife, Laura Goldy, watched cable news footage of Hurricane Harvey. The Category 4 hurricane dumped as much as 50 inches of rain in some parts of Southeast Texas and has left at least 38 people dead.

"I talked to her and said, 'I really feel like I need to go,'" said Brown.

He has joined throngs of volunteers who have come from across the country in the week since Harvey made landfall.

Those volunteers included many from the Philadelphia area. As of Friday, the Eastern Pennsylvania Red Cross had 29 volunteers responding or en route to Southeast Texas and other affected areas; 17 of them were from Philadelphia and its suburbs. The Red Cross' New Jersey chapter had 34 disaster workers deployed, with that count expected to rise to 45 by Monday.

Both states' emergency management agencies had deployed their "Task Force-1" response units earlier in the week, and volunteers from religious organizations and other aid groups were helping as well.

Among them was Kevin King, executive director of the Lancaster-based Mennonite Disaster Service, which helps with longer-term recovery efforts after search-and-rescue is complete.

"All the sights and the sounds playing through my mind over the last 48 hours," King said Friday, "it's overwhelming."

Over the last few days, King and three other members of the organization's assessment team have driven to affected areas to survey the damage. Their focus, he said, is on the poorer rural communities, which get less attention than big cities.

In one ravaged 600-resident town in coastal Victoria County, which bore the initial brunt of the storm, King said he came across a husband, a wife, and their four grandchildren.

"They're sleeping outside on a wet sofa under a makeshift tarp. They're sitting there, forlorn," King said, pausing as his voice caught. "Sorry, I try to stay cool …"

As King composed himself, he recalled that he had asked members of that family whether they had registered with the Federal Emergency Management Agency. They told King they had talked with FEMA, he said, but hadn't heard back. King said he told them, "We're coming back for you."

Mennonite Disaster Service plans to send teams of volunteers to the area over the weekend. King said those folks will work on "stage two" recovery, which includes mucking out and cleaning houses. In King's experience, this part alone could take nearly three months. Then, he said, crews will be deployed for "stage three," the part that involves rebuilding homes. That part could take years, he said.

King, a native of Lititz, Lancaster County, also assessed long-term recovery needs after Hurricane Sandy in October 2012 and Hurricane Katrina in August 2005. The devastation in Texas, he said, is among the worst he has witnessed.

"This hearkens back memories of Katrina," he said, noting, however, that cellphone service was not as widespread in the aftermath of Katrina.

Brown, the Red Cross worker who had never before been deployed to a disaster and expects to remain in the Houston area for about two weeks, said the experience has been even more chaotic than he expected.

Brown has experience in public relations, but when he arrived at the Red Cross' Houston headquarters, there was a need for help with getting supplies to shelters. Volunteers' roles are always changing, Brown said, and volunteers have been flexible in jumping on whatever assignment needs to be done at a given time.

It is easy to become overwhelmed, Brown said.

His assigned roommate, a Red Cross photographer, showed Brown aerial images of the city.

"The flooding is just devastating," Brown said. "On our way to the command center, we drove through a residential neighborhood. There were piles of debris down every side street. … You just see street after street, house after house."

But amid all the devastation, there are bright moments, too.

"Disasters have a way of tearing down fences, and you discover your neighbor all over again," King said. "There is no left nor right. There's no red nor blue anymore. It's neighbor helping neighbor."

Brown said, "The general mood down here is people are really looking out for each other and helping each other," And those whose homes have been damaged or destroyed, "they're worried, but they're optimistic. They think their community is going to help them."