By Audrina Bigos

CHICAGO (CBS) — Chicago firefighters spent several hours Monday afternoon extinguishing a stubborn fire under the Lake Shore Drive bridge over the Chicago River, after construction workers using a blow torch ignited wooden pilings.

Chicago Fire Department spokesman Larry Langford said “dolphin” pilings — wood bumpers to protect the bridge supports from boats — caught fire on the north end of the bridge late Friday morning.

Police said the fire started shortly before noon, and both northbound and southbound lanes of the bridge were closed as firefighters put out the fire.

At one point, there was zero visibility.

The fire appeared to be under control by about 12:30 p.m., and both sides of the bridge reopened a short time later, but the fire reignited around 1 p.m.

The city’s Office of Emergency Management and Communications said southbound traffic was being redirected at Grand Avenue, and northbound traffic was being redirected at Monroe Drive.

The Chicago Department of Transportation said the fire happened in a construction area under the bridge, where crews are working on the Navy Pier Flyover. Crews were using a blowtorch to remove and replace metal cap on a wooden “dolphin” piling when they accidentally ignited the fire.

The Fire Department said the fire was extinguished shortly before 4 p.m.

Sources told CBS 2’s Audrina Bigos the last time a piling in the river caught fire, it burned for three days, so the main goal was to get the fire out quickly.

Meanwhile, the pilings that caught fire Monday are all over the river. Wood pilings were also to blame for the Great Chicago Flood of 1992, which happened at Kinzie Street.

Back then, it was CBS 2’s Pam Zekman who broke the story of how the flood started. It turned out that when the city put in wood pilings, one of them caused a crack in a ceiling utility tunnel, which caused sub-basements of buildings to flood across downtown.