"Pictures don't do justice," he said. Looking down the street from the Habitat site, he said "there are no trees for three-quarters of a mile. It's like a giant lawn mower came through and mowed down everything."
He said "there's a lot of vacant land and a lot of new houses," but very few older homes; almost all of them were destroyed.
The effect on the community is difficult to imagine, he said. "Everybody knew one of the dead or injured."
The Habitat house is being build for Deborah Morris and her three special-needs children, whose house was destroyed in the storm. The family has lived in a shelter, a church basement and an apartment since the tornado, said Howard, who has sponsored 47 homes since he became involved in Habitat in 1996.
KRMG Radio in Joplin, which carries Howard's daily show, helped recruit volunteers, who have come from Georgia, Missouri, Illinois, North Carolina, Oklahoma and Mississippi. Howard estimated that 400 volunteers would work on the home by its completion in July or August.
A group of volunteers from Charity Baptist Church in Kannapolis, N.C., will be building all week at the site, Howard said.
The church group brought along a surprise gift -- $18,000 raised by a youth group through bake sales, car washes and allowances -- that will help fund another Habitat project in Joplin next year. The church will raise more funds to pay half the $65,000 to $70,000 cost and Howard will pay the rest.
Howard and his executive producer, Christa DiBiase, are broadcasting live from the site Tuesday from 1 to 3 p.m. on 750/WSB-AM.
Anyone who wants to donate to the effort can do so through the Joplin Habitat for Humanity website; designate the donation for Clark Howard's 2013 build.
AJC staff writer Rodney Ho and the Associated Press contributed to this article.