Emergency aid was delivered to residents affected by the Mississippi storm.

Dramatic footage shows trucks carrying tarps leaving the State Emergency Operations Centre on March 16.

The Mississippi Emergency Management Agency (MEMA) is also providing water and personnel to assist counties hit by the freak weather.

MEMA urged affected residents to file insurance claims, document home damage with photos, and report losses to county officials or through the agency's self-report tool.

Overall, at least 40 people were killed in the cross-country storm, officials said.

Twelve deaths were reported in Missouri, eight in Kansas, six in Mississippi, four in Texas, three in Arkansas, two in Alabama, and four in Oklahoma.