Huddersfield Giants have sacked coach Paul Anderson and assistant coach Kieron Purtill with the club second bottom of Super League.
Anderson, 44, took over from Nathan Brown in July 2012 and led the side to the League Leaders' Shield in 2013.
"It is with great sadness that we make this change," said chairman Ken Davy.
"We are not a hiring and firing club by nature. Unfortunately the simple fact is that the results this year have not been satisfactory."
He added: "The Giants are not performing to the level that anyone associated with the club expects.
"We have done everything possible behind the scenes to support the team and the staff in their quest for success."
Head of youth Andy Kelly has been put in charge of Huddersfield for Friday's Super League trip to Salford.
The Giants have lost 14 of their 18 Super League games this season and look set to enter The Qualifiers when the league splits after 23 matches.
Anderson's final match in charge was Sunday's 10-2 home defeat by local rivals Wakefield.
The former Great Britain and England prop had successful stints with Bradford Bulls and St Helens during his playing career before joining the coaching staff at Huddersfield in 2007.
Under Anderson, Huddersfield finished third in Super League in 2014 and 2015.