Overnight storms dumped a record amount of rain on parts of the Midwest, including more than 10 inches falling on Dubuque, Iowa, prompting fears of more Mississippi River flooding.

The hardest hit area appeared to be the Mississippi River town of Dubuque, Iowa, where more than 10.3 inches fell over the past 24 hours, prompting officials to close the city's flood wall along the river, which has risen over two-and-a-half feet since Wednesday.

The storm, which was accompanied by spectacular thunderstorms that lit up the night skies like a Fourth of July fireworks display, triggered numerous lightning strikes in Dubuque. One bolt "knocked off" a section of an apartment building, according to Dubuque Fire Chief Dan Brown.

"We did call in all personnel, the first time in my career that I remember that we've called all hands," Brown said.

"That order went out almost immediately when we saw the magnitude of this event."

Lightning strikes in Chicago and Detroit were blamed for blackouts and other electrical problems that left tens of thousands of people without power.

Fire fighters also rescued a few Dubuque residents from flooding homes. Dubuque Police Chief Mark Dalsing said most of the city streets that were closed last night due to flooding were reopened by mid-morning.

"One of the biggest draws of our resources last night was stranded motorists and cars that were getting struck in the waters, trying to sneak through swollen roadways," Dalsing said.

In Chicago, the storms knocked out power to more than 60,000 customers, according to ComEd. In Detroit, the utility DTE said 19,000 customers were without power.

The overnight storm brought Chicago's July total rainfall to nearly 10 inches, the most in more than 120 years.

It also provided temporary relief from the extreme heat that has baked the city and surrounding region for more than a week and caused at least 64 fatalities in 15 states, according to the National Weather Service.

The Julian Dubuque Bridge over the Mississippi River is closed and Highway 151 has been closed near Cascade as water is over both lanes of the road.

Dubuque Public Works director Don Vogt says his crews are busy picking up debris and finding manhole covers to make the city streets passable.

The Mississippi River is expected to rise another two feet on Thursday at Dubuque, Vogt said.

The weather service said 10.36 inches of rain fell in the past 24 hours at the Dubuque airport. Rainfall of 7.4 inches for Wednesday alone set a new record for Dubuque. The old record, of just over three inches, was set in 1896.

The Jo Davies County Courthouse just across the border in Illinois is closed, due to the rain, and some residents of East Dubuque, Illinois, were evacuated this morning. Reports along the Maquoketa River indicate some livestock were swept away in flash-flooding.