A manhole fire caused a loud explosion sound near Union Square Friday morning, the FDNY said. 

A call came in shortly before 8 a.m. about a fire in a manhole at Broadway and 12th Street, a spokesman said. The FDNY tweeted that multiple manholes were on fire, but did not have an exact number. 

People nearby tweeted that they heard a loud explosion sound. 

“Giant explosion behind me on Broadway as I was walking to work,” one user wrote.

The cause of the fire in under investigation.

From Long Beach to the North Fork, NewsdayTV's Elisa DiStefano and Newsday Deputy Lifestyle Editor Meghan Giannotta have ideas on how to hold onto the summer vibes after Labor Day. Credit: Newsday/Howard Schnapp; Morgan Campbell, Brian Jingeleski, Randee Daddona, Anthony Florio

Keeping the summer vibes alive after Labor Day From Long Beach to the North Fork, NewsdayTV's Elisa DiStefano and Newsday Deputy Lifestyle Editor Meghan Giannotta have ideas on how to hold onto the summer vibes after Labor Day.

From Long Beach to the North Fork, NewsdayTV's Elisa DiStefano and Newsday Deputy Lifestyle Editor Meghan Giannotta have ideas on how to hold onto the summer vibes after Labor Day. Credit: Newsday/Howard Schnapp; Morgan Campbell, Brian Jingeleski, Randee Daddona, Anthony Florio

Keeping the summer vibes alive after Labor Day From Long Beach to the North Fork, NewsdayTV's Elisa DiStefano and Newsday Deputy Lifestyle Editor Meghan Giannotta have ideas on how to hold onto the summer vibes after Labor Day.

SUBSCRIBE

Unlimited Digital AccessOnly 25¢for 6 months

ACT NOWSALE ENDS SOON | CANCEL ANYTIME