Severe thunderstorms with torrential rains and tornadoes killed four people, ripped roofs off mobile homes and trapped rush-hour drivers in flooded, tangled freeways Monday as a powerful series of storms hit Southeast Texas.

Nine members of one family were injured when their sport-utility vehicle skidded off rain-slicked Interstate 10 and hit a guardrail on their way home from a family gathering, said Harris County emergency management spokeswoman Gloria Roemer.

Harris County Sgt. Dana Wolfe said none of the injuries were life-threatening. Wolfe said one of the victims was a one-month old baby, who was not secured in a car seat and was ejected.

Two women were found dead in a sport utility vehicle in floodwaters between 8 and 12 feet deep in Houston.

Two others died in Brazoria County, southwest of Houston. One body was discovered in another submerged vehicle, and a 54-year-old woman died in a two-vehicle collision on a rain-slicked highway.

A tow truck driver pulled the SUV from a road feeding onto Interstate 45 in Houston and found the two bodies, said Police Lt. Tom Jennings. The victims were identified as Patricia Gutierrez, 36, and her daughter Melissa Rojas, 16, both of Houston. They apparently drowned, he said.

No other information was immediately available about the death in the other submerged vehicle.

Houston Police Sgt. P.E. Ogden III, who was waiting at the scene where the mother-daughter victims were found, said the floodwaters exert such pressure on submerged cars, "Arnold Schwarzenegger couldn't get out."

As much as 10 inches of rain were reported in the Houston-Galveston area overnight, closing numerous roads and some public school systems. Fort Bend County roads were closed, and widespread flooding was reported.

In Iowa Colony, south of Houston, the one-story brick house of Charles and Lee Anna Smith was an island amid muddy waters. Seats on a swing set in the backyard hovered just above the water and the couple's grandson was home from middle school.

The Smiths have been monitoring the water since the storms began Sunday, watching as their already saturated yard absorbed another 5-6 inches of driving rain through the night. The downpour finally stopped about 5 a.m. Bands of thunderstorms continued to pummel the Houston area throughout the day Monday.

"It's scary looking at all this water like this. It concerns me a whole lot," Charles Smith said as he looked at his submerged front yard. "If we get any more rain, it will be in my house."

In Hitchcock, near the Gulf Coast, a tornado tore the roof off a mobile home, but none of the six people inside were injured. Two other mobile homes sustained minor damage.

Galveston County emergency management coordinator John Simpson said the county had "sporadic" power outages, most of them near the trailer park struck by the high winds.

Simpson said dump trucks were blocking exits off I-45, preventing motorists from driving into flooded feeder roads.

Floodwaters began receding in Harris County by late morning. No power outages were reported, said Keith Lejeune, alert manager of the county's EMS. The city's two major airports experienced some delays.

Parts of Interstates 10 and 45 were shut down around Houston, and the University of Houston and several other schools were closed. Twenty bayous overflowed their banks, but county officials said no evacuations were ordered.

The storm spread as far east as the Louisiana line, where a tornado struck near the Jefferson County town of China, said emergency management spokeswoman Darlene Koch. The National Weather Service confirmed the tornado, and Koch said five mobile homes and two houses were destroyed. No injuries were reported.

Another tornado ripped through northern Newton County on the Texas-Louisiana line.

Koch said the Jefferson County storm brought 40-mph wind gusts and knocked over trees, causing some power outages in east Texas.

In the Texas Coastal Bend, as many as 20 homes were damaged as a suspected tornado roared through the small Lavaca Bay community of Magnolia Beach before daybreak Monday, Calhoun County Sheriff B.B. Browning said.

That was up to one-fifth of the homes in the town 75 miles northeast of Corpus Christi, he said. The only injury reported was a cut thumb a man suffered from flying glass, he said.

Up to 4 inches of rain overnight prompted flash flood warnings in parts of North and West Texas.

But by Monday morning, parts of Dallas County had only gotten up to 2 1/2 inches of rain, said Stacie Hanes, meteorologist with the National Weather Service in Fort Worth. Skies were mostly clear in the Dallas-Fort Worth area Monday afternoon.