A severe thunderstorm flooded the Denver Broncos practice fields Monday and caused damage to the parking lots and viewing areas at the empty UCHealth Training Center.

More than 3 1-2 inches of rain fell in an hour.

There weren't any crowds on hand because the storm struck on the players' day off.

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The team said it would close Tuesday's practice to the public as the cleanup continues.

Chip Conway, Broncos' vice president of operations, said grounds crews and other staff ''are working diligently to restore all necessary areas so that we can re-open ... as soon as possible.''

The Broncos closed training camp to the public last year during renovations but have been attracting around 5,000 fans a day this year.