(CNN) -- Rescue workers went house-to-house, building-to-building early Thursday searching for survivors after tornadoes cut a deadly and destructive path through western Massachusetts, officials said.
At least four people were killed and 40 injured when at least two tornadoes touched down in portions of Springfield, Mayor Domenic Sarno said.
Officials were investigating reports at least two more tornadoes touched down in and around the city, which is the third largest in Massachusetts.
"We are in triage right now," Sarno told reporters late Wednesday. "We are in life-saving mode."
As many as 19 communities reported tornado damage by Wednesday night, said Gov. Deval Patrick. At least one person was killed in Springfield, two in nearby Westfield and one in Brimfield, about 20 miles east, he said.
The governor declared a state of emergency as the storm system that spawned the tornadoes moved east, prompting storm watches all the way to the Atlantic coast.
By early Thursday morning, it was unclear how much of Springfield and its neighboring communities had been damaged, though there were reports of destruction coming in from every corner of the city, officials said.
"I can tell you the damage is extensive. It is very difficult getting around the city," Fire Commissioner Gary G. Cassanelli said. "The fire crews are having a tough time."
Up to 1,000 National Guard soldiers were expected to be on the streets of Springfield by daybreak to assist in search and rescue efforts and provide security on the streets, Patrick said.
Additional fire crews from Connecticut and New Hampshire were being dispatched to help with search and rescue efforts, the mayor said.
The storms struck shortly after 4 p.m. in Springfield, about 90 miles west of Boston.
At J.T.'s Sports Pub in Springfield, owner Keith Makarowski said he and the 10 or so patrons initially went outside to watch the darkening skies -- then retreated as the storm blew into downtown.
"There was a ton of debris flying around, lots of roof shingles and random siding," Makarowski said.
Several century-old buildings were damaged -- "roofs torn off, facades ravaged, trees uprooted" -- and a woman across the street was blown up against a building after being caught outside.
"Luckily, two people from inside the building were able to pull her in, and she seemed like she was OK," Makarowski said.
Residents were being warned to stay off the streets, many of which were impassable because of downed trees and power lines, overturned cars and debris from damaged and destroyed buildings.
Just outside Springfield in the community of Monson, resident Dolly Opper said state police were setting up roadblocks around the town, and a neighbor described the town's center as "war zone."
"The steeple's off the church across the street. It's lying right in the front yard," she said.
Springfield, Monson, Westfield and seven other towns -- Agawam, Charlton, Oxford, Palmer, Sturbridge, West Springfield and Wilbraham -- reported severe damage, said Massachusetts State Police Sgt. Michael Popovics.
State and federal officials hoped to be able to get their first aerial view of the damage at daybreak.
With 19 communities hit by the storm, Sen. John Kerry, D-Massachusetts, said he could not imagine that federal aid would not be forthcoming to the area.
Kerry also offered his condolences to those killed and injured in the storm.
"Clearly all of our thoughts and prayers are with those individuals," he told reporters late Wednesday.
Tens of thousands were without power after the tornadoes downed power lines and blew transformers.
Hard-hit areas might not have electricity until the end of the week, said Sandra Ahearn, a spokeswoman for the Western Massachusetts Electric Co.
Dylan McDonald said 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."
Television footage from CNN affiliate WSHM showed one tornado churn up water on the Connecticut River before it passed over a bridge with cars on it and moved into Springfield.
The tornado created a massive debris field, swirling giant pieces of wood, concrete and other materials at least 25 stories high -- in front of the tall downtown building that houses the affiliate.
The damage came amid a wave of heavy thunderstorms that moved through the Northeast on Wednesday.
Though not as tornado-prone as much of the Midwest or the South, Massachusetts has averaged two to three twisters per year since 1950, according to figures from the National Oceanic and Atmospheric Administration.
In 1953, a massive tornado that struck Worcester and nearby towns killed 90 people, according to NOAA.
