Hurrican Allen spent its strength against the Texas coast today and was downgraded to a tropical storm, a shadow of the mighty gale that churned across the Caribbean, leaving more than 100 dead in its wake.

Thanks to an early evacuation of about 200,000 people along a 450-mile stretch of coastline, no deaths were directly attributed to Allen's crashing entry on the Gulf Coast, although two people died of heart attacks while the storm was in the area.

But 20 people, many of whom had fled coastal areas in the path of the hurricane, were injured when a tornado it spawned hit a campground, where they had taken refuge, in San Marcos, north of San Antonio.

"We have about 20 in the hosptial," said Gary Nelson, assistant administrator at Hays Memorial Hospital. "Three or four have serious injuries."

Another tornado raked the airport at Austin, destroying three hangars, a National Guard weather trailer and 60 airplanes, including one owned by Lt. Gov. Bill Hobby. Damage was estimated at $50 million.

The swirling cloud, however, skipped over a church across the street from the airport where 1,500 people were attending services.

"We all got down and prayed," said Bill Moran, who was in the church. "We were thanking God after it passed on."

Earlier today, Allen hammered southern Texas with timber-ripping winds of 110 mph, flooding coastal cities, cutting off power and causing heavy damage to Texas' citrus industry. The seaport of Corpus Christi was swamped with the highest tides in 60 years, leaving beachfront property in shambles.

The diminished but dangerous storm had plowed across the resort of South Padre Island north of Brownsville early today and moved sluggishly into the mesquite-dotted land of the giant King Ranch, dumping flood-building rain of up to 7 1/2 inches. Tonight the storm appeared to be turning again, and was expected to drift into northern Mexico.

A 10-foot tide, the worst seen in Corpus Christi since a hurricane swept through in 1919, sent water up to the windows of homes. It was the first hurricane to hit Corpus Christi in a decade. Hurricane Celia in 1970 left 11 people dead and property damage estimated at $453.8 million.

Many Corpus Christi streets were blocked by felled trees, power lines and floodwaters. The splintered wreckage of pleasure boats and shrimp trawlers littered the marinas and some streets.

But if the damage was awesome, it was not as devastating as officals and residents had feared, and many were expressing relief. Much of the storm's punch had been drained away in the predawn hours, as the hurricane stalled half over land and half over water.

"We've been blessed," Texas Gov. Bill Clements said. "There's a great difference between what we anticipated and what we received. I think we've handled it very well. But God's handled it even better."

As the dangers lessened tonight, more than 50,000 of the evacuated residents of the battered Rio Grande Valley began leaving their shelters in schools, churches and other public buildings to return to their darkened homes.

The homecoming marked the end of a 36-hour vigil that began when the killer hurricane pointed its force toward Texas.

Saturday evening a team of meteorologists at the National Weather Service office in the Brownsville International Airport terminal, had ended its hurricane advisory with the words, "May God help us."

Outside, near-hurricane-force winds were already stripping street signs from their posts. Fifty miles east, the tightly constricted eye of Hurricane Allen had generated sustained winds of 170 miles an hour. Gusts up to 200 miles an hour were expected.

"Frankly, I was scared," said Richard Hagan, meteorologist-in-charge at Brownsville. "I was wishing my family was somewhere else."

At that time, the eye of the hurricane was tracking a course that would bring it on land just north of the mouth of the Rio Grande River, throwing the powerful north quadrant of the storm onto the resort at South Padre Island.

The hurricane, Hagan said, had developed internal pressures and wind speeds nearly identical to Hurricane Camille, which devastated the Gulf Coast near Biloxi, Miss., in 1969. Camille killed 200 people and leveled an area two blocks wide where its eye entered the coast.

But by 8 p.m. Saturday, Allen had come to a standstill 43 miles east of South Padre Island. The large spiral bands of the hurricane pounded the coast with 70 mile-an-hour squalls and torrential rains, but the winds at the heart of the storm slowly diminished.

"When it was out there for several hours, half of its circular arms were on land so it was deprived of half its energy source," said Jerry Cathey, a weather service meteorologist. "Nobody knows why it stalled, those things have a mind of their own."

Wheather service officials today found little structural damage to South Padre Island's numerous highrise hotels and condominiums, despite evidence that water had swept over most of the island.

But at the island's southern tip, the tiny fishing community of Port Isabel was not so lucky. Large chunks of the city had been swallowed by six-foot surf.

At the foot of a causeway that links Port Isabel with the island, a 100-yard-long fishing pier and a baithouse had vannished. On the opposite side of the causeway, a popular seafood restaurant was a shambles.

"It's real bad," said Port Isabel Major Quirino Martinez, who toured the town today in a four-wheel-drive pickup. Martinez pointed to a residential area where 90 percent of the homes had been either destroyed or severely damaged.

"I already contacted [Rep.] Kika de la Garza [D-Tex.]. I told him we were going to need some help to rebuild the town." The mayor said he had requested the congressman to obtain federal disaster funds to help the towns's 5,100 residents.

"Their wire reports were right." Martinez said of National Weather service advisories. "They said it was going to bring 15 or 20 feet of water in here, and they were right." As the mayor spoke, 150 armed National Guardsmen were deployed in Port Isabel to stand guard against looters.

Much of Port Mansfield, a fishing resort about 40 miles north of Brownsville, suffered heavy damage. Shot-gun-toting deputies kept evacuated residents and other people out of the town today because of the danger that butane and ammonia tanks would explode.

"We've got butane bottles leaking all over the place. We've got a lot of problems," said Willacy County deputy Glen Fisk.

Meanwhile, another feared spill -- crude oil -- failed to happen. A crippled Liberian tanker loaded with 11.8 million gallons of crude was rocked by hurricane-force winds, but remained aground off the coast near Corpus Christi. Coast Guard officials said the 37 crew members were safe and the vessel was in no danger of breaking up.

An insurance industry spokesman said it may be several days before the toll from Hurricane Allen is toted up.