In announcing Arniel's dismissal and the elevation of assistant Todd Richards to interim head coach, general manager Scott Howson said the season had "gone off the rails."
Under Arniel, the Blue Jackets were just 11-25-5 this season - the worst record in the NHL.
Richards was 77-71-16 as head coach of the Minnesota Wild from 2009-11. His first game leading Columbus will be Tuesday night in Chicago.
Howson announced the firing Monday, the morning after the club's latest dreadful loss: a 7-4 setback at Anaheim. The Ducks came into the game just one point ahead of the Blue Jackets' league-low 27 points but dominated throughout.
Howson said things had spiraled out of control recently.
"We were playing pretty good (after a bad start) until the middle of December and we were going in the right direction, but it's gone off the rails since then," he said on the team's website of the Blue Jackets' 2-8-1 mark since Dec. 15.
The Blue Jackets have blown eight games in which they led heading into the final period, the most in the NHL by a wide margin.
Just before meeting with the players on Monday morning, Richards said he did not plan wholesale changes.
"I've got a list of to-dos," he said. "I don't think it's big changes. It's little tweaks, little things here and there."
Arniel was hired as the fifth head coach in Blue Jackets history on June 8, 2010, and compiled a 45-60-18 record in 123 games.
In his first season, the Blue Jackets were a respectable 34-35-13 despite a lineup that included only one certifiable top-line player in perennial All-Star forward Rick Nash.
Last summer, Howson met the demands of many frustrated fans when he pulled off a major deal with Philadelphia to bring in high-scoring star Jeff Carter. Howson also traded for the rights to James Wisniewski and then signed him to a lucrative contract, locking up a puck-moving defenseman the franchise had long needed. Established veterans Vinny Prospal and Radek Martinek were also brought aboard.
But, for the most part, the season has been a disaster from the beginning.
Wisniewski sat out the first eight games for a head shot on Minnesota's Cal Clutterbuck in an exhibition game, and Carter was injured and missed games while Columbus stumbled to a 1-9-1 start - the worst in franchise history.
Martinek also has sustained a concussion which has kept him out most of the season. To add to the Blue Jackets' woes, Carter suffered a separated shoulder in Sunday night's loss at Honda Center and will likely be out for an extended period.
"I really divided our season into three parts and the first part, we had a tough start," said Howson, who decided over the weekend that it was time to make a change. "I didn't think it was a fair basis for evaluation because of the Wisniewski suspension and all the injuries. Really, if you look at our record from the middle of November to the middle of December, it was pretty good. We were playing good hockey. We were playing better defensively. I think we were 7-5-3 in a 15-game period. The 11 games since then we've only had two wins and our play seems to be regressing."
Richards, a loyal assistant who was saddened by Arniel's firing, said it was a situation where everything seemed to go wrong.
"I don't think you could have thought about or created a scenario that actually got to this point," he said. "I don't think you could sit and dream it up. Just the things that went on, how we lost games and how it snowballed and manifested into bigger things."
Arniel, the seventh NHL head coach to lose his job this season, joined the Blue Jackets after serving as head coach of the AHL's Manitoba Moose from 2006-10. He led the Moose to a 181-106-33 record and four Calder Cup Playoffs appearances.
But his message didn't resonate with players and the team never showed any consistency under him. The club started his first season with a 14-6-0 record, but since then it is 31-54-18 with only eight regulation wins in the last 63 games.
Richards, in his first year with Columbus, was named Minnesota's second head coach and led the club to a 38-36-8 record in 2009-10 and a 39-35-8 mark in 2010-11.
He was an assistant with San Jose in 2008-09 before being hired by the Wild.
Now he faces half a season with no incentive to make the playoffs and a world of questions about the future.
"It'll be different," said Richards. "It'll be a challenge."
Follow Rusty Miller on Twitter: http://www.twitter.com/rustymillerap .