New York, Dec 15 : The official death toll from the 30-odd tornadoes that attacked six central US states over the weekend has increased to 88 people, with 74 in Kentucky, which was hit the hardest, while at least 109 people in that state are still unaccounted for. US President Joe Biden on Monday declared emergencies in Illinois and Tennessee, which meant the two states will get federal help, and the President will visit Kentucky on Wednesday to survey the damage -- he approved its request for an expedited major disaster declaration on Sunday, Xinhua news agency reported. Rescue efforts resumed on Tuesday to identify the people killed in several states, and "family members have been phoning loved ones and gathering in living rooms across the American heartland, mourning those who had not survived the storms' swift, furious rampage," reported The New York Times. While rescue teams and volunteers combed through debris, "the unprecedented scale of devastation left behind by the storm began to come into focus," reported The Washington Post (WP). The National Weather Service said wind speeds reached an estimated 158 to 206 miles an hour at the peak of the storms. "For decades to come, meteorologists will focus on a particularly large supercell, or rotating thunderstorm, which spurred the tornado or series of twisters that caused the majority of the destruction, leading researchers to investigate if such events will happen more often in a warming world," said the report. During the disaster, homes and businesses had been torn from their foundations; two warehouses had collapsed, trapping and killing employees; hundreds of thousands of Americans were left without power in mid-December, forcing Kentucky and Tennessee to open shelters where people could warm themselves, according to WP. In hardest-hit Kentucky, the tornadoes derailed a train and scattered railcars in Earlington City in Hopkins County, and sent debris as high as 30,000 feet, the cruising altitude of many passenger jets. Governor Andy Beshear told reporters that the victims' "age range is 5 months to 86 years ... Six are under 18." In Illinois, six people were confirmed dead at an Amazon.com Inc. warehouse in Edwardsville, in the southwestern part of the state. The Governors of Arkansas and Missouri said two people died in each of their states, while Tennessee officials confirmed four deaths, according to The Wall Street Journal (WSJ). "The tornadoes caused catastrophic damage across a broad section of the country, in a swath that at times was as wide as three-quarters of a mile," said the report. "With this amount of damage and rubble, it may be a week or even more before we have a final count on the number of lost lives," Beshear was quoted as saying. Following a briefing from Federal Emergency Management Agency and Homeland Security officials, President Biden said on Monday that his administration was focused on helping restore power, water and communications systems and on providing temporary housing and shelter to displaced people. "We're going to have to go beyond what is available through the federal government ... There's a lot to be done and we're just getting under way," said the US President, adding that he was most concerned about the peace of mind and mental health of those who had lost their loved ones and their homes. "That's what worries me most -- the uncertainty ... The devastation is just stunning. And there's nothing left standing, basically, along the path that goes all the way through," said Biden, telling the media that he was working with the Kentucky Governor on the details of his forthcoming visit to the impacted areas there. Destinations of the presidential trip to Kentucky will include Ft. Campbell, where the US President will receive a storm briefing, and Mayfield and Dawson Springs, where he will survey storm damage, according to an announcement the White House issued on Monday morning. Mayfield was the focus of the tornadoes late Friday. "President Biden is navigating a politically fraught path on climate change after last weekend's deadly tornadoes, stopping short on Monday of directly blaming global warming for the disaster but emphasising the storms' extreme nature and ordering officials to get more definitive answers," reported WP late Monday. The US President, facing an unusual series of violent weather events during his first year in office, "has been forced to change the way Presidents have long dealt with natural disasters." A task that once involved calling local leaders, offering aid and consoling victims has expanded to far more politically sensitive terrain, said the report. Meanwhile, scientists are drawing clearer lines between global warming and destructive weather -- often prompting Biden to warn of the urgent need to address rising temperatures. And some climate activists say the tornadoes underline the urgency of swift action, according to the report. But Republicans are eager to pounce on any exaggeration of climate change's impact, putting pressure on Biden not to get ahead of what is verifiable. "We have to be very careful -- we can't say with absolute certainty that it was because of climate change," Biden said on Monday after officials briefed him on the tornadoes. /IANS