Former Daily Mirror editor Richard Wallace and Sunday Mirror editor Tina Weaver had no idea they were being axed when they arrived at work this morning.
The pair were told the news shortly after 10am by Mark Hollinshead, the managing director of Trinity Mirror's national titles.
Wallace was clapped out of the newsroom and his PA was reportedly seen clearing his desk shortly after.
He made reference to his sudden departure in a farewell email to staff, which ran to just three lines: 'After 22 years on the world's greatest paper it is time to move on - if rather unexpectedly!
'Thank you all for your fantastic work and invaluable support.
'It is critical the values of the Daily Mirror endure and you continue to give voice to our readers. Goodbye – and good luck."
Following their redundancies, which took place with immediate effect, People editor Lloyd Embley was appointed editor of both the Daily Mirror and Sunday Mirror.
Wallace's departure was all the more surprising for staff because in February he took over responsibility for editorial content across all three papers, when Trinity created a centralised reporting and production hub across the Daily Mirror, Sunday Mirror and the People.
The restructure saw around 80 editorial staff leave the papers, and many fear there could be another round of redundancies following the latest news.
Trinity declined to comment on whether there would be any further cutbacks after today's announcement, but management see today's news as the continuation of an integration strategy that began several years ago.
The new combined seven-day structure at the Mirror and Sunday Mirror is similar to the editorial set-ups that have been put in place at some of Trinity's regional hubs such as in Wales and Scotland. It also follows The Sun's move to seven-day publishing in February.
For Wallace, it brings the curtain down on a 22-year-career at the Mirror group.
He was appointed editor of the paper in June 2004 after Piers Morgan was sacked for publishing photographs - later shown to be fakes - which purported to show British soldiers abusing Iraqi prisoners.
He started his journalism career at the Leicester Mercury at the age of 18 and, after briefly working in marketing at EMI records, later joining the now defunct Ox and Bucks news agency.
After shifting with The Mail on Sunday, Wallace was recruited to the Mirror showbiz desk in 1990 by then editor Roy Greenslade. As showbiz editor he was responsible for creating the 3am Girls gossip page.
In October 2000, he became head of news, later overseeing the coverage of September 11 and the war in Afghanistan, which helped the Mirror win newspaper of the year in the 2002 British Press Awards.
After 15 months as New York-based US editor, he became Tina Weaver's deputy at the Sunday Mirror in August 2003 and was acting editor for four months when she went on maternity leave.
Weaver started her career at the South West News agency before joining the People in 1989 as a reporter. In 1993 she joined the Daily Mirror and a year later left for Today.
When the paper closed in 1995 she rejoined the Daily Mirror and became the paper's deputy editor in 1997. Weaver was appointed editor of the Sunday Mirror in April 2001 when Colin Myler resigned following the collapse of the trial in which two Leeds soccer stars were accused of assault, when the paper was found to be in contempt of court.
Embley was appointed editor of The People in June 2008, six months after he was made acting editor following the departure of Mark Thomas in November. Before joining the paper he held numerous backbench roles at the Daily Mirror including assistant editor.
Today's announcement comes one day after David Grigson took over as the new chairman of the company.
We'll have more on the shock departure of Wallace and Weaver in the first edition on Press Gazette's new digital weekly magazine tomorrow. Click here to sign up for your free copy of Press Gazette - Journalism Weekly