( CNN ) -- Officials in Joplin , Missouri , trimmed the list of people still missing Monday , more than a week after the most-deadly U.S. tornado in more than 60 years tore through the city . Twenty-nine people remain unaccounted for , down from 43 on Sunday , according to the Missouri Department of Public Safety . That figure includes three people whose families have reported them as dead . `` Our work will not cease until the number of unaccounted-for individuals is zero , '' said Andrea Spillars , deputy director of the Missouri Department of Public Safety . She acknowledged over the weekend that families waiting for information on missing relatives are frustrated the identification process has n't proceeded as quickly as they might have hoped . Authorities are relying on scientific identification of the remains . While that process is slow , it 's more reliable than a family member 's visual identification , Spillars said . The May 22 storm flattened buildings , destroyed neighborhoods and killed more people than any other U.S. tornado since modern recordkeeping began in 1950 . Early Sunday , Joplin City Manager Mark Rohr told CNN the death toll was 142 . State officials have released the names of 101 victims . Authorities have 146 sets of human remains , Spillars said Sunday , but some of the remains may belong to the same person and she cautioned against using that number as a death toll . Also Sunday , President Barack Obama visited Joplin , promising residents the support of the nation as they rebuild . The EF-5 tornado barreled into the city with 200-mph winds , reducing homes to unrecognizable rubble . `` Your country will be with you every step of the way , '' the president said to cheers . `` We 're not going anywhere . The cameras may leave , the spotlight may shift , but we will be with you every step of the way until Joplin is restored and this community is back on its feet . ''
29 people are still missing , down from 43 a day earlier . More than a week has passed since the deadly twister tore through Joplin . The death toll stands at 142 . Comment: