STATEN ISLAND, N.Y. -- So that's what it was...

The cause of the mysterious rattling noise that woke up scores of Staten Islanders around 3:30 a.m. on Tuesday was caused by a valve on a steam pipe let go at Cogen Technologies in Linden, N.J., according to Linden Mayor Derek Armstead.

The noise was caused by the escaping steam and was confirmed by the Linden Fire Department, Armstead said in a Facebook post.

For anyone awakened by the noise last night in the 7th ward, the Linden Fire department confirmed that a valve on a steam pipe let go at Cogen. The noise was the escaping steam. Posted by Derek Armstead on Tuesday, April 26, 2016

The Advance had received dozens of calls reporting the mysterious noise, and many others took to social media to ask about it.

Several took video clips.

The most clear one may have been posted by Facebook user Christina Cip:

Here's one posted by YouTube user Chris McKinley:

Here's another by YouTube user STiinyourface, who described it as a "loud banging":

Here's another from YouTube:



For several hours, the nature of the sound was a mystery to Staten Islanders who phoned the Advance and posted about it on social media.



Some readers described the long rumbling sounds that went on and off for a while as thunder, low-flying planes and a steam release from a plant in Linden, N.J.

One caller from New Springville said the noise was so loud it shook the windows and sounded like an explosion. Another man said it sounded like a plane going down.

A Port Richmond resident guessed that the noise was caused by planes hovering because of the storm.