HOUSTON, Aug. 27 (Xinhua) -- At least four people died from major category 4 hurricane Laura which made landfall on Thursday morning, leaving devastating destructions in U.S. southern states of Louisiana and Texas, local media reported.

Among the four dead was a 14-year-old girl who was killed when a tree fell on her family's home, Louisiana Governor John Bel Edwards said.

The governor warned that the number of casualties would grow as thousands of local, state and federal officials ran out to do search and rescue, survey damage and restore water and power.

Spared the worst case of flooding and storm surge, Louisiana is dealing with "tremendous damage" from winds caused by the storm.

According to local newspaper The Advocate, a riverboat casino was jostled loose and got wedged under the Lake Charles Bridge in West Louisiana on Interstate 10, causing the close of the highway.

Moreover, fire broke out at a chlorine gas chemical plant in the area, prompting a shelter-at-home order from the governor.

Besides, more than 600,000 homes and businesses were without power and it was not clear how long power would be out.

Louisiana Department of Health also said at least 67 water systems are "inoperable," meaning more than 200,000 people are potentially having trouble accessing clean water.

In neighboring state of Texas, Governor Greg Abbott on Thursday flew above the affected region with the U.S. Coast Guard to conduct a full survey of the damage.

Abbott said Orange city in East Texas was hit hard by the storm. "You saw more rooftops ripped off," said the governor. "You saw big pieces of steel framing wrapped around some trees. You saw some roads that were still inundated under water."

The powerful storm made landfall in Louisiana's Cameron Parish as a category 4 hurricane around 1 a.m. Thursday, making it the most powerful hurricane to hit Louisiana in 150 years. It brought screeching winds of a maximum speed of 240 kilometers per hour and heavy rainfall.

The storm has weakened to a tropical storm, bringing heavy rains and tropical storm force winds over parts of the state of Arkansas, the National Hurricane Center said.