ST. LOUIS (AP) - Three suspicious items that forced the several-hour evacuation of St. Louis' City Hall on Tuesday turned out to be two abandoned carbon dioxide canisters and a bag, all ultimately deemed harmless after their discovery forced the swearing-in ceremony of recently elected aldermen to be moved to a nearby park.
Investigators planned to examine video from City Hall's outside surveillance cameras to determine who placed the items near the building's entrances and why. The items were found by a City Hall worker before the sprawling building opened for business for the day, forcing the closure of nearby streets.
"In the post 9/11 world, we're very vigilant to what goes on downtown," Police Chief Sam Dotson told reporters after police determined the scene to be safe shortly after 11 a.m. Calling the items "very suspicious, very unusual," Dotson added "we want to make sure we get to the bottom of whoever did this, whether it's a practical joke or something more sinister."
Maggie Crane, spokeswoman for Mayor Francis Slay, said there were no known written or verbal threats, though Dotson said the suspicious items were clear evidence of a threat.
"Any time there's a suspicious cylinder on the steps of City Hall, there is a concern," Dotson said.
The police bomb and arson squad and several fire trucks were brought in, and three busy streets nearby - Clark Street, Market Street and Tucker Boulevard - were closed. Police carried out a controlled detonation of the bag, which a police bomb specialist in protective gear later inspected by hand and ruled safe. Crane said examination showed no dense material inside the canisters.
Dotson said police planned to check other downtown buildings to make sure no other suspicious items have been left elsewhere.
City Hall is at the southern edge of downtown, near several courthouses, including a federal courthouse. The City Hall building opened in 1898.
"It's a little disturbing, especially when you don't know why, what's behind it, if it's legitimate," Crane said.
The items were found one day after more than 100 people attended a meeting at City Hall at which the Board of Aldermen approved the formation of a civilian police oversight board. Members of the 28-member Board of Aldermen who were victorious during elections earlier this month were to have been sworn in Tuesday inside City Hall, but that ceremony took place in a nearby park, where they gathered, braving a strong wind, in a semicircle around a statute dedicated to St. Louis firefighters.
Lewis Reed, the board's president, said while it was alarming that someone would place potentially dangerous items on the City Hall's steps, the building's abundance of outside surveillance cameras left him confident the culprit or culprits would be caught.
"I'm sure they'll have footage of who dropped those canisters off," he said.
Workers assembled across the street but no other buildings near the area were evacuated.