[UPDATES BELOW] Large parts of Manhattan below midtown are now in the dark after a reported explosion that may have been at a Con Ed building. "Huge explosion at 14th st. All of downtown is now dark," tweeted Jesse Chan-Norris. Our own Chris Robbins adds that he saw a "massive explosion here in LES then all went dark." Check more tweets below, and we'll update once we learn more.
Huge explosion just rocked the East Village, everything went dark and I mean dark.#Sandy I'm now legit scared. twitter.com/buckyturco/sta…
— Bucky Turco(@buckyturco) October 30, 2012
Lights out, Manhattan. Creepy. From promenade. twitter.com/alananewhouse/…
— Alana Newhouse (@alananewhouse) October 30, 2012
Based on looking out my window, it appears that most of Manhattan south of Midtown may have lost power. Brooklyn still fine.
— Mike Epstein (@mikepstein) October 30, 2012
Power gone West Village Seventh Ave S near Christopher/W 10th/W 4th. Good luck friends!! Saving power now. Use landline if we need to know!
— Meg Hourihan (@megnut) October 30, 2012
Massive blackout now stretching downtown through lower Manhattan's West Side.... #Sandy
— Josh Elliott (@JoshElliottABC) October 30, 2012
Update: According to the Journal, Con Ed reports that a substation equipment failure knocked out power for 62,000 customers in Greenwich Village and Lower Manhattan. The utility also briefly lost power at its central command center near Union Square, but reportedly is back up now. Check out the photo below of the explosion that caused the power outage, seen from Williamsburg:
Here's another look at the transformer explosion:
And here's what Manhattan looks like from DUMBO, via Josh Reznick:
Here's an incredible shot of lower Manhattan taken from downtown Brooklyn by Dan Lurie:
It seems there may be one building still with power:
Friend texts: The only clearly visible building south of midtown that still has power is the Goldman Sachs HQ - every floor is still lit.
— Dana Rubinstein (@danarubinstein) October 30, 2012
And here's video of the explosion (around the :25 mark):
Here are some tips about how to conserve your cell phone power when the power goes out. And this is just too perfect:
Just herd NYC power went out?!?! Is that true
— Ryan Lochte (@ryanlochte) October 30, 2012
Con Ed spokesman Bob McGee has now confirmed that over 250K customers in Manhattan below midtown are without power. Specifically, he said that "pretty much everyone" south of 39th Street to the Battery are without power. Here are two more pics from inside the blackout:

On Lexington and 26th Street; looking north to Empire State Building (Matt Lee)
And here's what the World Trade Center looks like now:

Christopher Torella
There are more reports of people trapped in homes and at the LES Con Ed plant, as well as evacuations at NYU Hospital:
Manhattan: FDR Dr & East 14 St FDNY on scene at the Con-Ed Plant to Removed Several Con Ed Workers who are Trapped inside by High Water.
— NY Scanner (@NYScanner) October 30, 2012
NYU HOSPITAL WITHOUT POWER, THEIR GENERATORS ARE NOT WORKING. STARTING TO TRANSPORT PATIENTS. #SANDY #911BUFF
— 911 OPERATOR(@911BUFF) October 30, 2012
Sea Gate: Flood Waters Very High People R Trapped In There Homes And Have Been Forced To Go To Second Floor..Cars R Said To Be Floating Away
— Worldwide Actions (@AlwaysActions) October 30, 2012
Verified, & worst news I've heard so far: NYU hospital generator failed. Personnel manually evacuating PICU & NICU down 9 flights of stairs.
— Kathryn Schulz (@kathrynschulz) October 30, 2012
Over a million New Yorkers are now without power:
#NYS POWER #OUTAGE update 10PM: 1,374,312 NYers without power #Sandy
— Andrew Cuomo (@NYGovCuomo) October 30, 2012
Update: Con Ed said that the substation could be repaired by the end of the week. It was apparently flooded by 6 feet of water and added, "No Con Edison employees are trapped in a building. The story spreading is a rumor." However, the video of the explosion could be real, since there was an explosion