Dean Smith has been sacked as Norwich City head coach after a run of just three wins in 13 Championship matches.
Assistant manager Craig Shakespeare and first-team coach Liam Bramley have also left Carrow Road.
Steve Weaver and Allan Russell have taken caretaker charge of the team.
“As the club continues to work towards its on-field objectives this season, the board believe that it is the right time to make this transition,” Norwich said in a statement.
“The club will now work to identify and appoint a new head coach that is able to deliver both the level of performances required to challenge at the top end of the league whilst implementing a consistent style of play.”
Smith publicly questioned the attitude of some fans after the home defeat by Blackburn on 17 December and said playing away was better for his side.
“I think a lot of them have been waiting for this period to happen, or wanting it to – I don’t know,” he told BBC Radio Norfolk at the time.
Monday’s 2-1 defeat at Luton was a third defeat in four.
Canaries sporting director Stuart Webber added: “This was a tough decision, but one that we felt was necessary to give ourselves the best possible chance of achieving our objective of promotion to the Premier League this season.
“With just under half of the season remaining and three consecutive home games on the horizon we now have a real opportunity to build some forward and positive momentum, both on and off the pitch.”
The Canaries had been top of the table on 1 October but are now fifth and 12 points off the top two.
Smith was appointed as Daniel Farke’s successor in November 2021 but was unable to save them from relegation back to the Championship last season.
Farke won the second-tier title twice during his four and a half years at the helm, but on each occasion they only lasted a single campaign in the Premier League.
Smith began his managerial career at Walsall before moving on to Brentford and then Aston Villa.
He guided Villa to promotion from the Championship in 2019 and they reached the Carabao Cup final the following year.
The former defender was sacked following five successive Premier League defeats at the start of the 2021-22 season, only to take the Norwich job eight days later.
‘Smith failed to convince fans of style’ – Analysis
Phil Daley, BBC Radio Norfolk sports editor
Norwich City haven’t clicked all season and ultimately that’s why fans demanded change.
Even during their nine-game unbeaten run in September and October, the football on offer wasn’t convincing. Fans were still scratching their heads as to exactly what Dean Smith’s style was.
As Sheffield United and Burnley started to pull away at the top of the division, questions were piling up as to when things might click – with a squad who have won this league before.
The World Cup break bought Smith time – a month to get his squad fired up – but there wasn’t much fire on the resumption.
Defeat by Blackburn at Carrow Road was the beginning of the end as fans couldn’t take it any more.
Instead of fans leaving early, it was boos during and after the game – they wanted change now.
Had Smith won convincingly at Luton, that might have been enough to buy another couple of home games to prove what he was capable of… but we all know how that went.
Ultimately, it was the failure to convince the fans his football was up to scratch that led to his departure.