As the remnants of Hurricane Harvey drenched Houston and the water rose, those were the city’s darkest days. That is when we saw the brightest lights shine, lights like Major Marty O’Brien and Deputy Richard Jue.

“He called me Sunday morning. He said, ‘Get going. Get your stuff. Let’s go,’” Jue recalls.

This emergency near Beltway 8 and Hardy Toll Road was the first scene Deputy Jue and Major O'Brien responded to on Aug. 27.

The pair, who’ve known each other since 1982, loaded up the airboat and headed to northeast Houston.

“We were on the Beltway headed over to Tidwell and Beltway 8,” O’Brien said. “That’s when you came running after us and flagged us down.”

WATCH: KHOU 11 crew helps save truck driver

He’s referring to KHOU 11 reporter Brandi Smith, who was doing a live report on that overpass. Photographer Mario Sandoval spotted a truck stuck in several feet of water with driver Robert Roberson still inside. Though the deputies hadn’t been headed Roberson’s direction, they were after seeing his situation.

Major Marty O'Brien and Deputy Richard Jue rescued driver Robert Roberson out of his flooded truck on Aug. 27.

Major O’Brien says it took a bit to find a good place to put the airboat in, but before long, he steered that airboat right up to Roberson’s passenger window.

“We pulled up and I said, ‘Are you all right?’ He says, ‘Yeah, I think so. I’m pretty wet,’” Jue said. “I looked around, and you could see all of the items floating in the water. He was in pretty bad shape.”

WATCH: KHOU 11 crew reunites with truck driver rescued during Harvey

They got Roberson back on land and, eventually, to a shelter. Then they just kept going.

“We did hundreds of rescues, to be honest with you, in the four days in the airboat,” O’Brien said.

Wherever folks needed help, Jue and O’Brien were there. Before you dismiss those rescues as just being a part of their job, think again. The pair are reserve deputies, volunteers who have full-time jobs.

In addition to being a reserve deputy for Harris County, Marty O'Brien owns Southland Hardware.

Major O’Brien runs his family-owned Southland Hardware, so even when he’s not saving lives, he’s still helping people.

Jue’s family owns China Garden downtown. He says being a deputy offers a change of pace.

“It is different. Yeah, it is,” Jue laughs.

They are just two of more than 200 reserve deputies working for Harris County. During the worst of Harvey, that group saved hundreds of lives.

Richard Jue and his family owns China Garden, one of the longest-running Chinese restaurants in Houston.

WATCH: In their own words, Brandi Smith, Mario Sandoval recount trucker rescue

“They rescued 963 people, 150 dogs and 60 cats,” says Chief Deputy David DeLeon. “We have some of the finest people working under the reserve command who work tirelessly for the people of Harris County, people like Major O’Brien and Deputy Jue, who, when they see something occurring, take action and do something about it.”

During the darkest hours for the city and Roberson, those deputies provided hope and humanity to the rest of us in Houston.