Wimberley - Floodwaters kept rising on Tuesday across Texas as the search continued for 30 missing people and storms dumped more rain on the Houston area, stranding hundreds of motorists in the nation's fourth-largest city.Among the missing was a group who disappeared after a vacation home was swept away and slammed into a bridge.Houston authorities recovered three more bodies from the flood waters, bringing to 11 the number of people killed by the holiday weekend storms in Oklahoma and Texas.Crews also searched for victims just across the Texas-Mexico border in Ciudad Acuna, where a tornado killed at least 13 people on Monday, including an infant who was ripped from its mother's arms.Firefighters in Houston carried out more than 500 water rescues, mostly stranded motorists. At least 2 500 vehicles were abandoned on the streets by drivers, said Rick Flanagan, Houston's emergency management coordinator."It's absolutely massive," Texas Governor Greg Abbott said after touring the destruction.Some motorists were stuck on Interstate 45 all night, sleeping in their cars.NBA fans at a Houston Rockets game on Monday were asked not to leave the arena because of the severe weather. About 400 people remained in their seats at 01:30, choosing to stay in the building.Some of the worst flooding damage in Texas was in Wimberley, a popular tourist town. The Blanco River crested above 12m, more than triple its flood stage. It swamped Interstate 35, and rescuers used pontoon boats and a helicopter to pull people out.A spokesperson for the flood district of Harris County, which includes Houston, said up to 700 homes had some level of damage.The deaths in Texas included a man whose body was pulled from the Blanco; a 14-year-old who was found with his dog in a storm drain; a student who died on Saturday after her car was caught in high water; and a man whose mobile home was destroyed by a reported tornado.The Oklahoma Department of Emergency Management reported four deaths between Saturday and Monday after severe flooding and reports of tornadoes.In Ciudad Acuna, Mayor Evaristo Perez Rivera said 300 people were treated at local hospitals after the tornado, and up to 200 homes had been destroyed.Rescuers were looking for four members of a family who were believed missing.