The disastrous flood that hit downtown Chicago on Monday began as a small and seemingly harmless leak that was detected at least a week earlier by city workers.
The seepage was considered routine at the time it was spotted, and plans were made to make repairs from within the tunnel.
But before the work began, the leak grew into a flood that sent more than 250 million gallons of murky Chicago River water coursing through a turn-of-the-century underground tunnel system and up into the subgrade levels of buildings throughout downtown.
Early Monday, the seepage became a torrent that roared through a hole in the roof of the tunnel that runs beneath the river`s bed. By the time stunned city workers lowered a sonar device into the river to measure the breach, the hole had grown to the size of an automobile.
City officials said that a South Side firm identified as Great Lakes Dredge and Dock had done work last year, between June and September, in the river near the site of the leak. But officials said they haven`t determined whether that work was related to the seepage discovered by city workers in recent days.
Mayor Richard Daley on Monday night said that earlier construction work in the area was being considered as a possible culprit and acknowledged that city employees knew about the leak ”a number of days or a number of weeks”
ago, adding that those employees had, as a reporter`s question put it,
”dropped the ball.”
”The information was filed in the system,” Daley said. ”Each and every person who had information will be accountable to me and to the people of the city of Chicago.”
The mayor described those with early knowledge of the seepage problems as ”high-ranking” public works officials.
Asked if city workers had failed in handling the incident, Daley added:
”Individuals did, not the city.”
Within hours of the rupture Monday, electrical power to many Loop buildings and natural-gas service to a few was shut down. Without electricity, lights went off, office machines couldn`t function, elevators didn`t work, and pumps that send drinking water up through buildings shut down.
Tens of thousands of workers were sent home, some trekking down dim stairwells. Trials at the Daley Center were halted. The aisles at Carson`s and Marshall Field`s went dark. City Hall was evacuated. The Chicago Board of Trade and Chicago Mercantile Exchange closed. And a throng of about 500 gawkers gathered at Kinzie Street and the river to watch city workers dump tons of gravel, sandbags and finally quick-setting cement in an attempt to plug the devastating leak.
Daley at first reacted defensively to questioning about the flood`s cause, refusing throughout most of the day to assess blame for the disaster that shut down the central business district.
But David Mosena, Daley`s chief of staff, revealed later that city inspectors had noticed the seepage in an old tunnel beneath the river at Kinzie Street 7 to 10 days ago.
”Leakage is not a unique experience,” Mosena said. ”But a collapse of this sort is unique.”
The rupture took place at a spot in the tunnel just west of the Apparel Center and the Merchandise Mart near the Kinzie Street bridge.
Thomas Kennedy, executive vice president of the Merchandise Mart, said that city crews sought and received access into the affected stretch of tunnel from his building Wednesday and either Thursday or Friday.
”I assume (leakage) was going on for some time for it to build up this much pressure,” said Mack Hanson, an official with the city`s Board of Underground, which monitors subterranean systems and passageways. ”This isn`t something that happened overnight.”
Hanson speculated that the leak may have begun two or more weeks ago and that the severity of the problem was discovered early Monday only after water rose into Loop basements and alarmed tenants began to phone emergency numbers. At the point of the breach, the river is about 26 feet deep, and the tunnel is 14 to 19 feet below the river bottom, Hanson said. The tunnel is eliptical in shape, 7 feet 6 inches tall at its highest point and 6 feet wide at its widest point.
Mosena said that pilings near the bridge, and only a few feet from the hole, were replaced in a city-state project that was completed last fall. Pilings, which protect bridges from collisions with vessels, routinely are replaced when they deteriorate, he said.
Mosena said that it was only speculation that the piling replacement project may have been related to Monday`s disaster, but officials offered no other explanation for the cause of the leak. And, the mayor said, it was
”high-ranking” public works officials who had knowledge of the seepage problem before Monday.
But late Monday, Daley, without disclosing details of what work was done, said the replacement project was being studied in an effort to pinpoint the the cause of the leak.
Mosena said there was no additional recent work by private developers in the area.
Sorting out liability for the disaster and who will foot the bill will take years of legal wrangling in the courts.
At earlier appearances at the Kinzie site and City Hall, the mayor brushed aside questions about what precipitated the flood and said that determining the cause of the disaster was not important when compared to the need to stop the leak.
”The construction was over six months ago,” he said. ”At this time, we`re going to stop the water from flowing. We are not going to get into who is to blame.”
Daley later in the day said he would appoint a committee to determine the cause of the flood. Isolating the cause and determining if officials had certain knowledge of problems before Monday will play a role in sorting out liability for the disaster. Experts said that deciding who foots the bill likely will take years of legal wrangling in the courts.
Chicago`s underground tunnel system, about 60 miles long, was built shortly after the turn of the century to transport coal to Loop buildings and permit ash and other refuse to be removed.
Hanson said that portions of the system contain various cables that are checked periodically for damage. But the section where the rupture took place wasn`t checked as regularly as others because it contains no utilities.
He said the tunnel in that section is made of concrete that is 10 inches thick, but not steel-reinforced as would be required if the tunnel were built today.
Electrical power in the downtown area bordered by the Chicago River on the north, Adams Street on the south, Michigan Avenue on the east, and Dearborn Street on the west could be out from 24 to 48 hours, Commonwealth Edison Vice President Donald Petkus said late Monday.
Monday night, Paul McCoy, manager of transmission and distribution operations for Commonwealth Edison, said that during the worst of the flooding, 900 Edison customers were without power.
Power might be restored on a building-by-building basis, Petkus said.
To most of its victims-downtown businesses and workers-the massive flood was an invisible disaster.
The Loop was filled with the sounds of sirens as fire trucks rushed to and fro, but the streets were bone dry.
By mid-morning, at least a dozen high-rises had some flooding in basement levels. But the biggest problem turned out to be a loss of electricity as Edison cut off substations in a precautionary move that affected scores of buildings.
Downtown workers first were advised to evacuate the area bounded by Washington Street on the north, Adams Street on the south, Dearborn Street on the west, and Michigan Avenue on the east. The zone later was expanded to the stretch from the Chicago River on the north, Taylor Street on the south, Michigan on the east, and Canal Street on the west.
By 9:30 a.m., signs already were up in the windows of Carson Pirie Scott & Co.`s State Street flagship saying, ”STORE TEMPORARILY CLOSED DUE TO FLOOD.” Farther north on State, similar advisories were in Marshall Field & Co.`s windows.
”Are we going home?” asked one worker in the State of Illinois Center around mid-morning.
”I hope so,” said another.
Two hours later, state employees were sent home.
In the bowels of City Hall, water rose to a depth of 30 feet, said Dan Weil, the city`s building commissioner. The building has several subterranean levels, including a direct connection to the tunnel system.
Fire Commissioner Raymond Orozco advised workers in the affected area to call their bosses Tuesday to see whether they should report to work.
The flood and the resulting loss of electricity caused the Chicago Transit Authority to shut down the State Street and Dearborn Street subways. Trains on the Howard-Englewood-Jackson Park, which normally run through the State Street tube, were detoured onto the Loop elevated structure.
But trains on the O`Hare-Congress-Douglas line stopped short of downtown, running truncated routes. Shuttle buses were pressed into service to fill the gap.
Illinois Bell customers were not affected directly by the flooding because their cables are just below street level. However, a company spokesman said that a high volume of calls were coming into the downtown area and going out, comparable to times of big snowstorms. And some problems with phone service were reported.
Matt Rodriguez, who was named police superintendent Monday, said staffing in the affected area would be beefed up.
More than 100 additional officers were assigned to the downtown area during the day on Monday, officials said. At 6:30 p.m., those on duty were replaced by 215 officers working overtime or drawn from special duties.
Emergency lighting equipment from the suburbs was called in to supplement city hardware to illuminate portions of the area. The city also planned to bring some of the regular street lighting up by using emergency generators.
Meanwhile, police directed traffic at Loop intersections where traffic lights no longer functioned.
Attempts to plug the hole in the tunnel apparently stopped a whirlpool in the river by Monday evening, Mosena said, and the seepage was minor.
But because it was not known whether the closure was complete, he said the city planned to dig straight down into Kinzie Street on either side of the break and sink huge steel walls into the tunnel to ”encapsulate” the area.