HOUSTON, Aug. 27 (Xinhua) -- At least six people, including a 14-year-old girl, died from major category 4 hurricane in the southwest coast of U.S., media reported.

Making landfall on Thursday morning, the hurricane is said to be the most powerful hurricane to hit the state of Louisiana in 150 years.

Governor John Bel Edwards 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.

Edwards said wind from Laura did the most damage, with storm surge falling short of projections. The governor warned the storm did "extensive" damage that is ongoing as it continues to move inland.

An estimated 600,000 homes and businesses were without power and it was not clear how long power would be out.

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

Greg Abbott, governor of the neighboring state Texas, said on Thursday there was no report of deaths in Texas so far. But he noted that it was premature as Hurricane Laura "continues to sweep through Texas in an unprecedented fashion."

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

The storm brought screeching winds of a maximum speed of 240 km per hour and heavy rainfall.

It has weakened to a category 2 hurricane just after 5 a.m., bringing rains and tropical storm force winds over parts of the state of Arkansas, the National Hurricane Center said.