At least 13 of the 25 hospitalized, including 10 firefighters, were in fair to serious condition, most with smoke inhalation, said Larry Langford, the Chicago Fire Department's public information officer. Two firefighters were in critical condition.
Firefighters were able to make headway after getting hoses to the top of two 26th floor roof wings. They then shot water three floors up to the 29th floor, where the blaze started, but the flames rekindled spreading to the 30th floor, WMAQ-TV, Chicago, said.
About one-third of all Chicago Fire Department equipment was dispatched to the fire along with 15 ambulances. The Chicago Fire Department requested help from suburban fire departments around four hours after the blaze began to protect the rest of the city.
The 29th floor of the LaSalle National Bank Building houses the office of the bank's chief economist, the bank's trust department and treasury research offices. Those offices are staffed at all hours of the day and night, working with businesses around the world.
Reports several hours after the blaze was reported indicated nobody was trapped in the building, which was constructed in 1934, before fire sprinklers were required in high-rise structures.