Texas still reeling from deadly floodwaters

A relentless and deadly cycle of rain and floodwaters is creating a crisis in Texas. More heavy rain and lightning lashed areas around Dallas overnight. Some parts of the state have seen more than a foot of rain this month alone.

Storms have killed at least 17 people in Texas and Oklahoma since the weekend, and more than a dozen are still missing.

Across the Houston area, people are recovering from a devastating flood that paralyzed much of the city. Six hours of relentless rainfall flooded streets and highways, causing thousands to abandon their cars and trucks, and thousands of homes have been damaged, reports CBS News correspondent Vicente Arenas.

The bayous that overflowed have started to recede but the aftermath of this historic flooding is still being felt.

"We've had ten days two weeks of steady rain. The grounds were completely saturated, and there's really been no place for the water to go," Houston Mayor Annise Parker said.

911 operators fielded nearly 2,300 calls, many of them from stranded drivers needing help from first responders.

Two people are missing after their rescue boat coat capsized, and 66-year-old Dennis Callahan died of a heart attack while helping a woman push her car, which had stalled in the water.

"I'm going to remember him as my best friend and he was everything you could ask for in a father," his son Michael said. "That's what kills me is he was literally a block away from his home."

Crews rescue storm victims from historic Texas flooding

Devastating scenes are being captured across the area, including one showing the inconsolable grief of a man after he learned one of his relatives had drowned inside a truck.

Others are more uplifting. Four strangers risked their lives to help a woman and her dog after their car was trapped by the quickly rising waters.

Some 4,000 homes were damaged in the flooding. One of the hardest hit areas was the Houston community of Meyerland.

With the threat of more severe weather on the way, Texas' governor has issued an emergency declaration for Houston and is warning drivers not to take any chances.

"Do not drive into rising water," Texas Gov. Greg Abbott said. "I know it may seem like something you can easily traverse, but it is something that is incredibly powerful and can sweep you away just like it has so many others in the state of Texas in the past week."

Many of those are still missing. A frantic search continues for nearly a dozen people ranging in age from 4 to 81, reports CBS News correspondent Don Dahler.

Crews desperate to find a dozen missing in Texas flood

Crews combed the shoreline of the Blanco River by land and air Tuesday, surrounded by mangled reminders of Saturday's deadly storm.

"We have over 150 personnel continuing to scope the river looking for any survivors," one person said.

Three families from Corpus Christi were staying in a Wimberley vacation home that was washed away by the floodwaters. Laura McComb, her 6-year-old son Andrew and 4-year-old daughter Leighton are among those still missing.

"She told me around 11 o'clock that water had started coming in," her sister Julie Shields said.

McComb was texting with Shields during the storm, then the phone rang.

"One o'clock in the morning she called me. She said, 'I'm in a house, I'm floating down the river. Tell Mom and Dad 'I love you' and pray," Shields said.

McComb's husband, Jonathan, survived, with a broken sternum, rib and punctured lung.

"He is absolutely devastated. He did everything he could to save them," Shields said.

A man is comforted after finding out that a relative drowned in her truck at 5757 Ranchester in Houston on Tuesday, May 26, 2015. Thomas B. Shea/Houston Chronicle via AP

Two-hundred fifty additional volunteers are aiding the search effort; some are using a nearby church as home base.

"This is a moment of crisis for these families and you do whatever you can to help," one person said.

Family members of the eight missing from Corpus Christie remain hopeful and grateful. In a joint statement they said, "The search remains an active search. ... We have been overwhelmed and strengthened by the outpouring of support."

Tuesday, emergency response crews found two people alive.

The drenching rain threatened to linger, according to The Associated Press. National Weather Service forecasts called for a 20 to 40 percent chance of thunderstorms through the rest of the week in Houston, and more storms were also in store for Central Texas.