"If there was asbestos, the good news is with all the water generated by the steam, most of the asbestos was washed down," Bloomberg said, which may have resulted in "relatively little in the air."
At least three firefighters received minor injuries, and more than 20 other people were hurt, some seriously, Bloomberg said. The accident shut down subway lines, and caused brief panic among passersby.
Rain and thunderstorms pounded the area most of the day, and Bloomberg said the most likely cause of the explosion was "cold water getting into the pipe, and cold water apparently causes these to explode."
In 1989, a steam explosion in New York's Gramercy Park killed three people and sent a geyser of white-hot steam 18 stories into the air.
That blast, which blew out windows and showered buildings with asbestos, was caused by the condensation of water inside a steam pipe.
Some water mains in the city are 150 years old, Bloomberg said.
Steam pumps through mains beneath the city 24 hours a day, heating and cooling thousands of buildings.
There is always the danger of an explosion, the mayor added, but it is rare.
"We couldn't be prouder of how New Yorkers behaved in this incident," the mayor said.
People "helped each other, and [that's] exactly what you would expect," he said. "It's an inspiring thing for all of us."
--
erika.hayasaki@latimes.com
