CASTEL BOLOGNESE, Italy—Exceptional rains Wednesday in a drought-struck region of northern Italy swelled rivers over their banks, killing at least eight people and forcing the evacuation of thousands.
The heavy rains also forced Formula One to cancel this weekend’s Emilia-Romagna Grand Prix to not overtax emergency crews that were already stretched thin in responding to the rivers of mud that have torn through the region, wreaking havoc on infrastructure and homes.