More updates below, but here's a summary so far (8:20PM): A steam explosion occurred on East 41st and Lexington Avenue (41st between Lex and Third) just before 6PM - right during the evening rush hour. The NYPD does not think it was a terrorist attack. It appears that there is a hole about 25' in diameter with a red tow truck in the center. One person has died (possibly from cardiac arrest) and there are at least 15 people injured. It is a six-alarm situation for the FDNY, which includes 24 engines and 13 ladders.

Mayor Bloomberg just called it a "failure of our infrastructure." There are 4/5/6 train service disruptions in Manhattan (no 6 between 59th and Brooklyn Bridge; no 4 between 86th and Brooklyn Bridge; no 5 - it's running on the 2); the S is suspended; the 7 is bypassing Grand Central in both directions (update from MTA). Metro-North is operating (use north entrance at Grand Central).

Our commenters have many insights, too.


BREAKING 6:03PM: There are reports of an explosion near Grand Central Terminal. Apparently manhole may have exploded around East 48th and Third Avenue, with many people injured. Officer workers in the area tell us they were told to stay in their offices. Train traffic into Grand Central may be impacted as well.

1010WINS says on their website: "A large transformer has exploded at 41st Street between Third and Lexington avenues, according to the FDNY."

Traffic is being shut down in the vicinity and buildings are being evacuated.

Update 6:20PM: Some reports say that a steam pipe exploded on East 41st. The area between East 41st and 47th is being cleared. Metro-North service is running normal, but the 4/5/6 service may be diverted.

It's a 4th alarm fire situation, with two injuries (one may be a young man with burns).

A reader at Lexington and East 46th tells us that people are either walking uptown very quickly or standing around to take cameraphone pictures.

Update 6:32PM: The NYPD does not believe it was a terrorist attack. The AP reports, "A large column of gray smoke poured from the vicinity of a building near Grand Central Terminal and the Chrysler Building, and the air near the site was filled with ash."

Reader Sean writes us:

I happen to live 3 blocks south of the explosion & it's right out my window. The scene is calm now that police have arrived. But my whole building is vibrating from the rumble of the high-pressure venting. There is steam spewing out of the ground at very high velocity (almost volcano-like); it has torn a 2 lane wide hole in Lex just north of 41st.

The fire is now at 5 alarms.

Update 6:51PM: Whoa - footage on the local news is crazy - steam is still erupting. A WABC 7 reporter says chunks of asphalt were spewing from the explosion. Another WABC reporter spoke to a person who lives on the 27th floor in a nearby building and saw rocks and debris flying up by his window!

Update 7:01PM: There are at least two people injured (possibly critically). While there are FDNY and NYPD units on the scene, the concern is now that there is asbestos contamination.

Update 7:07PM: Reader Nick sent us this video of the explosion. All we can say is whoa.

Update 7:14PM: WNBC 4 is reporting that Con Ed did turn off the steam to that pipe (there was an earlier report about not being able to turn off steam completely, or else there would be an explosion - not sure if that's still the case), but it'll take some time for the steam to stop escaping.

Reader dadoc explained that there was a similar steam explosion in 1989 at the corner East 20th & Third Avenue on a Saturday (three people were killed in that incident).

NYC Transit Authority spokesman Paul Fleuranges tells WNBC that there's no 4/5/6 service between Brooklyn Bridge and East 86th.

Update 7:42PM: The steam will be turned off slowly. MTA (and our readers) reports 4/5/6 service is suspended in both directions between 125th and Bowling Green. The local news stations keep bringing up how it's very much like September 11 when talking to witnesses.

And reader dadoc also points out a good graphic about the city's steam system from a 2005 Gothamist post. We're going to upload some info about the "water hammer" effect (here's a Wiki definition) in a few minutes.

Update 7:54PM: Now it's a 6 alarm situation. WNBC reports that one person taken to Bellevue has died. And Chopper 4 is showing a red tow truck in the hole, which is about 25 feet by 25 feet.


Update 8:07PM: Mayor Bloomberg is on his way to the scene. The Office of Emergency Management official speaking to WNBC pleads that the public should not come to the Grand Central area.

8:21PM: Mayor Bloomberg is speaking. A 24" steam pipe broke; the pipe was installed 1924. Cause seems to be cold water getting into the pipe. There are so many alarms and sirens going off, the press conference has temporarily halted. It's unclear where the cold water is from - this morning's rain or a water main break. No power outages (thanks to redundancies that cover the area), some Verizon outages. Too early to tell how long it'll take it fix, but the Mayor hopes it'll be relatively back to normal tomorrow. The big concern is that there may have been asbestos released in the air; they'll know in an hour, but one somewhat positive thing is that there was so much water, hopefully the water the trapped it.

Frozen zone is between 40th to 43rd Street, Vanderbilt and Third Avenues.

Emphasis on being cautious and not rushing out to the street. Would like public not to come to the area.

NYPD: Many street closures - traveling crosstown will is closed on many streets between 34th and 54/59th.

DEP: Erring on side of caution; air monitoring and sampling. Gives props to Con Ed for cleaning out their steam units. Hopes to have test results in hour or so.

Department of Health: Close windows. If there's AC, turn it on to recirculate the air. If people were exposed to debris, wash with soap and water. Put your clothes in a plastic bag. No way to test asbestos exposure yet, but be careful.

Back to Mayor, who says that he's proud of how New Yorkers reacted - from emergency responders to regular people on the street:

We couldn’t be prouder of our New Yorkers. The people that should respond knew exactly what to do and how to cooperate and work together, and the person in the street understood that we’re all here together and they knew not to panic. They rushed around, helped each other. It's what you would expect, it’s inspirational to all of us.

He suggests mass transit, versus driving into the area, in the morning.


Update: Watching NY1's The Call, and one person pointed out there's a strong steam smell on the west side of Lexington Avenue near Grand Central and asks "Couldn't this have been anticipated?"

Reader Bill writes about his familiarity about the steam corner:

Con Ed had been working on that 41/lex corner for a while and much of the NE corner was covered by those gigantic steel plates (which were really hot—you could feel the heat radiating up through your shoes). Steam is always coming out of the ground there (and has been vented in the recent past through those orange chimney-like things). Also, a couple of weeks ago, I was heading into the office one morning and crossed that street in the heaviest steam cloud I’ve ever seen on an nyc street. When I got into the middle of it, it was a total whiteout condition and I was worried that I was going to walk into someone coming in the opposite direction.

Photograph at top of the steam on East 41st between Third and Lexington Avenues by Joseph Marty/AP; video by Nick Parish; middle photograph of tow truck in hole by WNBC; photograph at bottom by ~Raymond on Flickr