A series of tornadoes swept across the Midwest Tuesday night, killing at least four and leaving shattered houses and downed power lines in their wake. Three of the reported deaths occurred in Harrisburg, Ill., where as many as 40 homes were destroyed. A fourth life was claimed in a trailer park near Buffalo, Mo., where 13 other people were injured. Another eight people were injured overnight in Harleyville, Kan., when what appeared to be a tornado touched down in the town, causing Gov. Sam Brownback to declare a state of emergency.