2 women dead after being swept away in severe San Antonio flooding

At one point Saturday, a storm and subsequent floods had knocked out power to about 12,000 customers and spurred the closure of dozens of streets in the Texas city and the surrounding county, authorities said.

Scores of people had to be evacuated due to floods and other issues, and Fire Chief Charles Hood noted there had been about 250 water-related calls -- in addition to ones for things like medical emergencies, accidents and more -- in the first 15 hours of Saturday.

The greatest concern had to do with people getting too close to fast-moving, deceptive and unpredictable floodwater, CNN reported.

"We're asking folks to observe low-water crossing (warnings), to use common sense and to stay off the road if possible," Mayor Julian Castro said.

The first confirmed fatality -- a woman around age 30 -- was reported around 7:30 a.m. (8:30 a.m. ET), and her body was about three hours later, police Chief William McManus said.

Some time later, an older female driver went into water that was 4 feet above flood markers. Firefighters got to her vehicle and broke a window -- with one firefighter cutting his hand -- Hood explained. Then, as the would-be rescuers tried to get her from her vehicle, "the currents changed and washed that vehicle away," the fire chief said.

The woman's car had rolled on top of rescue boat, forcing out the firefighters who'd been in it, fire department spokesman Christian Bove later explained. By the time the firefighters were able to climb back into the boat, her car had become submerged in about 25-foot deep water and was gone.