PORT ARTHUR, TEXAS — Hurricane Laura roared ashore on the border of Texas and Louisiana as a Category 4 storm early Thursday morning, ripping apart buildings, severing power lines and clogging streets with debris as a dangerous storm surge trailed behind. With sustained winds of 150 mph, Laura's eye made landfall near Cameron, Louisiana, at about 2 a.m. ET before plowing a path of destruction north toward Arkansas, where the weakened storm was predicted to then curve east through Kentucky and Tennessee by Friday evening. By 5 a.m. ET, sustained winds were still 120 mph and the storm had dropped to a Category 3 hurricane, forecasters said. While Laura was expected to weaken rapidly into a tropical storm by this afternoon, forecasters continued to warn of flooding danger. "Catastrophic storm surge, extreme winds and flash flooding ongoing," the National Weather Service said in a 4 a.m. update, with the worst of the storm surge expected to travel up the Calcasieu River area. "The eyewall of Laura will continue to move inland across southwestern Louisiana during the next several hours." The latest developments: Damage is expected from Sea Rim State Park, Texas, to Intracoastal City, Louisiana, including Calcasieu and Sabine lakes. Late Wednesday, the National Hurricane Center warned tornadoes were possible in southeastern Louisiana and extreme southwestern Mississippi. Interstate 10 eastbound at the Texas-Louisiana border and westbound west of the Atchafalaya Basin is closed. The Cajun Navy Relief & Rescue, the legendary nonprofit flotilla of privately owned boats used to assist flooding victims, was gearing up for rescues. This file will be updated throughout the day. For updates in your inbox, subscribe to the Daily Briefing. Fierce rain pounds Port Arthur, Texas From Port Arthur east to Lake Charles, Louisiana, transformers exploded with showers of sparks, plunging neighborhoods into darkness as windows shattered, and heavy rains lashed the area as the 25-mile-wide eye moved north at about 15 mph. The National Weather Service said accurate rainfall totals were not yet available, and several radar and transmitter sites appeared to have been damaged by the storm. Overnight, videos shared by stormchasers and reporters deployed across the area showed portions of building roofs ripped off by the high winds, which also toppled a large RV in Lake Charles. Throughout the night, forecasters warned those who had not evacuated to expect both tornado-force winds and tornados being spun off by the hurricane. Stormchasers and meteorologists said a full accounting of the damage wouldn't come until dawn. Sunrise is at 7:47 a.m. ET in Lake Charles, and observers said it appeared many roads were blocked by debris. – USA TODAY's Rick Jervis from Port Arthur, Texas Largest evacuation operation in US amid coronavirus More than half a million people were ordered to evacuate Tuesday, the largest evacuation in the U.S. amid the coronavirus pandemic. Emergency officials with Jefferson County, which includes Port Arthur, staged a number of “hubs” to collect residents and transport them to other areas around Texas, rather than shelter them there, said Allison Getz, a county spokeswoman. A key reason for doing it that way was concerns over the coronavirus pandemic, which makes it hard to shelter large groups of people in one place, she said. Only 15 to 20 people were being placed on buses, instead of the usual 50, she said. – Rick Jervis Tracking Hurricane Laura🌀: Get the latest info on Laura's path and forecast with USA TODAY's storm tracker. Hurricane Laura is first major hurricane of the 2020 season Once Laura's winds whipped up to beyond 110 mph on Wednesday, it became the first "major" hurricane of the 2020 season. The Atlantic hurricane season has been a record-breaker. Laura is the earliest L-named storm in the Atlantic Basin, breaking a record held by Luis, which formed Aug. 29, 1995. This season has had 13 named storms, which is well above-normal activity. Forecasters knew this season would be particularly active. Earlier in August, the National Oceanic and Atmospheric Administration said up to 25 named storms could form in 2020. Up to 11 could be hurricanes, NOAA forecasters said. “This is one of the most active seasonal forecasts that NOAA has produced in its 22-year history of hurricane outlooks," said U.S. Secretary of Commerce Wilbur Ross in a statement. – Doyle Rice Marco, Laura:What happens if we run out of names? Study from May: Global warming is making hurricanes stronger Is climate change to blame for the devastating effects of hurricane winds? Maybe. A study published in May found human-caused global warming has strengthened the wind speeds of hurricanes, typhoons and cyclones around the globe. Scientists studied 40 years of satellite images to reach their conclusions and found the chances of hurricanes becoming a Category 3 or higher have increased each of the past four decades. "Our results show that these storms have become stronger on global and regional levels, which is consistent with expectations of how hurricanes respond to a warming world," said study lead author James Kossin of the National Oceanic and Atmospheric Administration. – Doyle Rice Contributing: The Associated Press. Jervis reported from Port Arthur.