At least 19 people have been killed after tornadoes ripped across the US state of Tennessee, shredding at least 40 buildings.
One of the twisters caused severe damage across the centre of Nashville, destroying the stained glass in the historic East End United Methodist Church and leaving hundreds of people homeless.
Daybreak revealed a landscape littered with blown-down walls and roofs, snapped power lines and downed trees, leaving city streets in gridlock.
Schools, courts, transport lines, an airport and the state capitol were closed, and some damaged polling stations had to be moved only hours before Super Tuesday voting began.
Tennessee Emergency Management spokesperson Maggie Hannan said the death toll jumped to 19 on Tuesday after police and fire crews spent hours pulling survivors and bodies from wrecked buildings.
Nashville Mayor John Cooper said: “Last night was a reminder about how fragile life is.”
Emergency crews closed off roads in the historic Germantown area.
Roofs had been torn off apartment buildings, large trees were uprooted and debris littered many sidewalks.
Walls were toppled, exposing living rooms and kitchens in damaged homes. Mangled power lines and broken trees came to rest on cars, streets and piles of rubble.
State governor Bill Lee said: “It is heartbreaking.
"We have had loss of life all across the state.”
He ordered all non-essential state workers to stay at home before going up in a helicopter to survey the damage.
The tornadoes were spawned by a line of severe storms that stretched almost 800 miles from near Montgomery, Alabama, into western Pennsylvania.
In Nashville, it tore through areas transformed by a recent building boom.
Germantown and East Nashville are two of the city’s trendiest neighbourhoods, with restaurants, music venues, high-end apartment complexes and rising home prices threatening to drive out long-time residents.
One tornado reportedly stayed on the ground for about 10 miles into Nashville’s eastern suburbs, following a path parallel to the Interstate 40 road and causing more damage in Mt Juliet, Lebanon, Hermitage and other communities.
Several aeroplane hangars were destroyed and power lines were downed at John C Tune Airport, Nashville International’s sister airport in West Nashville.
Airport spokesperson Kym Gerlock urged people to stay away until further notice.
Metro Nashville Public Schools said its schools would be closed because of the tornado damage.
Wilson County, just east of metro Nashville will close schools for the rest of the week.