This is all ABC has right now:

Tom Ridge is resigning as secretary of homeland security, ABC News has learned.

Ridge, the former governor of Pennsylvania, has sent his letter of resignation to President Bush, sources told ABC News.

A formal announcement is expected later in the day.

OK, you're saying to yourself, "wouldn't just about anyone else do a better job?" or "aren't all Bush appointees pretty much the same?" Well, consider that a possible successor is Asa Hutchinson, last mentioned here. Check out the links at the end of that post to see what this might mean.

UPDATE: Here's a (Freudian slip?) from the AP, the Washington Times, or Ridge himself:

Homeland Security Secretary Tom Ridge has informed the White House and department staff that he has resigned, U.S. officials said today.

In an e-mail circulated to senior Homeland Security officials, Ridge praised the department as "an extraordinary organization that each day contributes to keeping America safe and free." He also said he was privileged to work with the department's 180,000 employees "who go to work every day dedicated to making our company better and more secure."

Compare that with this version of the AP report:

In a much anticipated move, Homeland Security Secretary Tom Ridge, whose name became synonymous with color-coded terror alerts and tutorials to the public about how to prepare for possible attack, announced Tuesday that he was stepping down.

In an e-mail circulated to senior Homeland Security officials, Ridge praised the department as "an extraordinary organization that each day contributes to keeping America safe and free." He also said he was privileged to work with the department's 180,000 employees "who go to work every day dedicated to making our country better and more secure."

At post time, news.google.com shows 99 with "country" and 86 with "company", the earliest for both being 11am Pacific time. Perhaps someone with access to the raw AP feed can weigh in.

For more on the DHS, see Red Alert.

To see the leading lights of the blogosphere weigh in on this announcement, go here or here. A comment from the last link on Ridge's replacement: I nominate the US Marine who killed the the playing-dead enemy in Falluja. Just having that man's picture at some airports would be a deterrent.

UPDATE 2: That's odd. See the link in post #8. It concerns the order of succession for DHS and involves FEMA, and it's from yesterday. And, for some unknown reason, some FEMA regions are not included; see the map in post #49.

UPDATE 3: Hutchinson gets defended in post #172; a report of a San Diego townhall meeting with Tom Ridge is in post #174.