"This is causing significant and life-threatening flooding countywide".
McDowell County Emergency Management sent a message to the public around 10:15 a.m. Wednesday saying engineers have determined the dam at Lake Tahoma is safe.
"We understand people are getting anxious concerning the length of the evacuation order". State inspectors will evaluate the risk during daylight hours. Once again please be patient. Personnel worked through the night performing swift water rescues and are still going door to door informing residents of the situation.
Two deaths had been reported during the storm's passage.
William Kehler, McDowell County Emergency Services director, told NBC News that "several thousand" people lived in the mandatory evacuation zone.
The soggy remnants of Alberto moved toward the nation's interior Tuesday, leaving scattered flooding and downed trees in the wake of the year's first named tropical storm.
Numerous showers and thunderstorms capable of producing heavy rainfall are expected to approach the region Thursday afternoon and continue past midnight, according to the National Weather Service. It is reported that the landslide was provoked by heavy downpours.
A motorcyclists drives away after checking out where the French Broad River flooded into Lyman Street in the River Arts District in Asheville, N.C on Wednesday, May 30, 2018.More news: US team in North Korea raises expectations of a Trump-Kim summit
Lake Tahoma is a private lake in the mountains, in McDowell County.
Residents living below Lake Tahoma were ordered to leave after the dam was inspected by an engineer.
"Ivy Creek's normally a very docile creek, but with 8 to 10 inches of rain.it turned into a swollen, raging river", he said, "and it just tossed and turned both of those vehicles".
In Virginia, flash flooding blamed on Alberto turned a peaceful creek into a roaring death trap as witnesses reported a man and woman were swept away when their auto was washed off a road Wednesday night. Roads have been closed in Avery, Buncombe, McDowell, Watauga, Henderson, Rutherford, Macon, Polk, Mitchell, Transylvania, Gaston, Catawba and Iredell counties, the governor's office said.
Alberto weakened to a subtropical depression Monday, but millions of people in parts of Alabama, Tennessee, Georgia and Kentucky were still under flash flood watches for much of Tuesday.
Two deaths had previously been reported in the USA during the storm's passage.
Minor power outages were reported in north Florida, and the state's emergency response team started closing shelters on Monday, citing a lack of need. A tree fell on their SUV as they covered the hazardous weather, the station said.
Alberto, the first named storm of a hurricane season that won't officially start until Friday, made landfall Monday west of Panama City on Florida's Gulf Coast, delivering heavy rains, surging seas and winds of 45 miles per hour.