"I haven't seen such devastation in a long, long time," Pence said in hard-hit Kokomo, where at least 32 people were injured and about 50 homes were destroyed.
The storms that hit Indiana on Sunday were part of a wave of severe weather that cut across the Midwest, killing six people in Illinois and two in Michigan.
The National Weather Service said preliminary findings indicated a low-level EF3 tornado of at least 158 mph struck south of Lafayette and at least six EF2 tornadoes packing wind speeds of 111 to 135 mph struck other parts of Indiana. The EF2 twisters included one on the ground for 10 miles that hit Kokomo, a 12-mile tornado in nearby Grant County, and one in southwestern Indiana's Knox County that traveled 19 miles.
Two tornadoes of undetermined intensity struck western Indiana, near Covington and near the Montgomery-Tippecanoe county line. Tornadoes also were reported in two other southern Indiana counties and northwestern Indiana's Jasper County.
The storms cut power to thousands, tore off roofs, damaged schools and left mountains of debris where homes once stood.
About 30,000 homes and businesses, mostly in northern and central Indiana, remained without power Monday. Several school districts canceled or delayed classes because of power issues or damage.
Damaged structures ranged from a 110-year-old post office in the historic Indianapolis community of Irvington to grain silos, houses, factories and a coffee shop in places including Lafayette, Lebanon, Washington and Vincennes.
The storm that hit Kokomo was the worst to hit the city since a deadly tornado on Palm Sunday in 1965, the Kokomo Tribune reported.
"In my lifetime, this is the worst tornado we've ever experienced," said Mayor Greg Goodnight, who was born a few days after the 1965 twister.
Even so, many residents counted their blessings as they searched for belongings amid the wreckage.
Phyllis Rawlins, 59, said losing the two-story Victorian-style house she and her late husband built about eight years ago was hard, especially since the storm came about a year after her husband's death.
"This is a severe loss, after losing him," she said.
But she was grateful that her granddaughter, Chelsea, and friends from church survived. They were in the house when the storm struck and got to the basement just before the tornado lifted the house, moving it 100 feet away onto train tracks.
Chelsea suffered a broken ankle, and the others had broken bones and cuts, Rawlins said.
Patsy Addison, a 62-year-old homemaker, also was feeling fortunate. She sought shelter in a hall closet in her home Sunday and didn't have time to close its door before a large maple tree crashed through her home.
The tree landed less than a foot from the closet, showering Addison with insulation but leaving her uninjured.
"The tree was where I was standing seconds before," she said Monday. "I'm thankful to God that I'm still here."
She surveyed her home Monday with her husband, Robert, who summed up the damage matter-of-factly.
"Houses can be rebuilt, lives can't," he said.