David J. Phillip, Associated Press
Members of Cameron County Sheriff's Department rescue Leticia Reyes, right, from a home surrounded by floodwaters from Hurricane Dolly on Wednesday near Los Fresnos, Texas. The Church of Jesus Christ of Latter-day Saints moved more than two dozen missionaries inland until the hurricane passes.

BROWNSVILLE, Texas — Hurricane Dolly barreled into South Texas on Wednesday, lashing the coast with winds up to 100 mph and dumping heavy rain that flooded some low-lying areas but spared levees along the heavily populated Rio Grande Valley.

Authorities had feared the first hurricane to hit the U.S. since last September could produce up to 20 inches of rain in some areas, possibly breaching levees in the heavily populated Rio Grande Valley. But shortly before its center came ashore, the Category 2 storm meandered 35 miles north of the border, veering away from the flood walls.

"The levees are holding up just fine," said Johnny Cavazos, emergency coordinator for Cameron County. "There is no indication right now that they are going to crest."

The Church of Jesus Christ of Latter-day Saints moved more than two dozen of its missionaries to safer areas.

Church spokesman Scott Trotter said that, as a precautionary measure, 28 missionaries in the Texas McAllen Mission have been moved inland until the hurricane passes.

"All missionaries have checked in and are safe," he said.

Although the system weakened to a Category 1 hurricane shortly after crossing the resort area of South Padre Island, officials cautioned that the danger had not passed. About 5,000 people went to public shelters in three Texas counties hit hardest by the storm.

More were expected as night fell and at least 53,000 customers were left without power.

"Hopefully people won't get stupid and go out and think the storm has passed," said Kevin Pagan, the manager of an emergency center for the three counties.

Most of the destruction from wind was on the island, where the hurricane knocked out power to thousands of homes, ripped off roofs and smashed windows.

Roads and yards were strewn with toppled trees, fences, power poles and streetlights. Business signs rolled around the streets like tumbleweeds. The causeway linking the island to the mainland was closed.

A 17-year-old boy fell from a seventh-story balcony, injuring his head, breaking his hip and fracturing his leg. The boy was being treated at an island fire station. It was not immediately known if the accident was directly caused by the storm.

As Dolly weakened Wednesday night, authorities turned to watch for flooding caused by the inches of rain being dumped across Texas and Mexico.

Between 5 and 12 inches of rain had fallen in Brownsville's Cameron County by Wednesday evening and another 3 to 7 inches was expected during the night, according to the National Weather Service. Estimates in Laguna Vista and Bayview reached 12 inches.

Small communities just north of Brownsville were hit by high winds and flooded with murky waters from the storm, including low-lying colonias, small villages of immigrants who live without sewer and water service. A family of eight had to be rescued by sheriff's deputies when floodwaters surrounded their home.

No deaths were immediately reported in Mexico, but Tamaulipas state Gov. Eugenio Hernandez said 50 neighborhoods were still in danger from flooding. About 13,000 people had taken refuge in 21 shelters, he said.

"Strong winds are no longer the problem. Now we have to worry about intense rain in the next 24 hours," Hernandez said.

Earlier in the day, Mexican soldiers made a last-minute attempt to rescue people at the mouth of the Rio Grande, using an inflatable raft to retrieve at least one family trapped in their home. Many people further inland refused to go to government shelters.

At 8 p.m. EDT Wednesday, the storm's center was about 60 miles northwest of Brownsville and moving west-northwest at about 10 mph. The storm's maximum sustained winds had weakened to about 75 mph. Forecasters expected to downgrade it to a tropical storm later Wednesday night.

Dolly spawned thunderstorms as far away as Houston, 400 miles up the coast. Tornado watches were in effect for many coastal counties between Corpus Christi and Houston.

Many Texans heading north were stopped at inland Border Patrol checkpoints, where agents opened extra lanes to ease traffic flow while still checking documentation and arresting illegal immigrants, said sector spokesman Dan Doty. At one checkpoint on U.S. 77, smugglers were caught with nearly 10,000 pounds of marijuana.

The U.S. Census Bureau said that based on Dolly's projected path, about 1.5 million Texans could feel the storm's effects. Gov. Rick Perry declared 14 south Texas counties disaster areas and sought federal disaster declarations.

As Dolly approached, oil and gas companies in the Gulf of Mexico evacuated workers from 62 production platforms and eight rigs, according to the U.S. Minerals Management Service, which monitors offshore activity.

Shell Oil, which didn't expect production to be affected by the evacuations, also secured wells and shut down operations in the Rio Grande Valley, where it primarily deals in natural gas.

The last hurricane to hit the U.S. was the fast-forming Humberto, which came ashore in South Texas last September. Dolly is the 26th hurricane to make landfall in the U.S. in July since record keeping started in 1851, according to federal researchers.

The busiest part of the Atlantic hurricane season is usually in August and September. So far this year, there have been four named storms, two of which became hurricanes. Federal forecasters predict a total of 12 to 16 named storms and six to nine hurricanes this season.