Updated

An apparent tornado demolished a jail building and overturned several vehicles early Sunday, authorities said.

No injuries were reported. The National Weather Service said the storm was reported about 5:15 a.m. in southern Pasco County, just north of Tampa.

One of two minimum-security annex buildings at the Pasco County Jail in Land O' Lakes was destroyed, sheriff's spokesman Doug Tobin said, but all of the inmates had been evacuated moments earlier into the main jail.

"A few seconds after shutting the door," Tobin said, "is when that structure basically collapsed."

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The destroyed building was a temporary structure to ease overcrowding. Tobin said it housed about 125 female inmates. A county Web site describes it as a "tensioned-membrane structure that is designed to withstand 110-mile-per-hour winds."

A second annex, housing about 100 male inmates, was free of any serious damage, Tobin said. The main prison building, which holds about 950 inmates, sustained roof damage.

A cold front that moved east into the Tampa Bay area combined with the remnants of Tropical Storm Olga to generate strong thunderstorms from the Tampa Bay area north to around Brooksville in Hernando County before dawn Sunday, said Paul Close, a meteorologist with the National Weather Service in Ruskin. The tornado was spawned from the heavy storms.

A weather service meteorologist was working in Pasco County on Sunday to try to determine the path and the strength of the apparent tornado, Close said.