WASHINGTON (CNN) -- A staged news conference during the California wildfires last month claimed the job of a second Federal Emergency Management Agency press official, as a review of the incident revealed "a calamity of bad decision-making."

Aaron Walker, press secretary for FEMA, submitted his resignation to the administration's chief David Paulison Wednesday afternoon, according to a FEMA official. The official would not say whether Walker was asked to resign or did so voluntarily. His resignation becomes effective in early December.

The official said Walker and John "Pat" Philbin, who was FEMA's director of external affairs, bore the "greatest degree of responsibility for the planning and execution" of the news conference.

"They had the greatest ability to stop that train from going down the track, and they didn't," said the official.

Philbin left his job two days after the news conference to become head of public affairs for the Director of National Intelligence, Mike McConnell. That job offer, however, was rescinded as Philbin's role in the press conference became clearer.

FEMA officials hurriedly called a press conference on October 23, giving media outlets only a few minutes notice. When no reporters were present for the conference, FEMA staffers asked questions of the agency's No. 2 official, Harvey Johnson. Reporters were allowed to call in for the conference, but they were kept in listen-only mode and not allowed to ask questions.

In a phone interview with CNN Wednesday, Philbin said, "It happened on my watch. I should have known better. I should have done more."

Philbin blamed a series of bad decisions. "It wasn't done maliciously," he said.

A just-completed review of events leading up to the press conference reached the same conclusion.

"There was no indication of malicious intent ... or any preconceived effort to deceive the media or the public," Russ Knocke, the Department of Homeland Security official who conducted the review, told CNN.

Instead, Knock said, there was "a calamity of bad decision-making."

The review uncovered an email sent by an unnamed staffer just minutes before the press conference telling employees of the FEMA press office to fill the empty seats in the auditorium and "spur discussion." In addition, as the press conference began, a member of FEMA's senior staff encouraged and even instructed other FEMA staffers to ask questions. Philbin said he is not that senior staff member.

No one tried to stop the session, said Knocke, even though some employees did have misgivings.

The review also discovered that the email advisory notifying the press of the news conference was delayed for about nine minutes while officials tried to confirm satellite coordinates for a live broadcast of the event. Software glitches further delayed the email's transmission, and some reporters only got the advisory at around the time the press conference was scheduled to begin, the review found.

Homeland Security Secretary Michael Chertoff called the faux press conference "one of the dumbest and most inappropriate things I've seen since I've been in government."

The incident prompted FEMA to issue new guidelines for dealing with the news media intended to prevent the incident from happening again.

The new Standard Operating Procedures, issued Friday, bar government employees from asking questions at "any Agency organized press event." They also call for notification of the media at least two hours -- "but at a minimum, no less than one hour" -- prior to the start of a news conference.

The new procedures also require two-way conference lines for media use when possible and say that "listen-only" lines will never be used.

Knocke said employees of the FEMA press office will also be receiving training from public relations and press organizations on various subjects, including ethics. E-mail to a friend

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