One person was killed in Springfield, two in nearby Westfield and one in Brimfield, about 20 miles east, Massachusetts Governor Deval Patrick told reporters Wednesday night.
The storms struck shortly after 4 p.m. in Springfield, about 90 miles west of Boston. Dylan McDonald told CNN he watched the tornado knock down trees and scatter debris across town as he was driving with a co-worker.
"As the light turned green, a tree fell and everything took off," McDonald said. "We saw a roof fly off an apartment building. The car was tilting, but didn't turn over."
As many as 19 communities reported tornado damage Wednesday evening, Patrick said. The governor declared a state of emergency as the storm system that spawned those twisters moved east, with watches posted all the way to the Atlantic coast until late Wednesday.
"It's been particularly devastating in downtown Springfield," Patrick said. And he said a local official told him, "You have to see Monson to believe it."