Platoon Chief Joe Armstrong says she might have been in the water for as long as a couple of minutes but was out by the time fire crews arrived.
She appeared to be none the worse for wear but was taken to hospital as a precaution against hypothermia.
The fire department was also later called to the Transit building on the east side for a leak of natural gas in the boiler room. The building was evacuated and aired out before the people who work inside were allowed back.
