O'Brien was let go a day after the team dropped its fourth straight game to start the 2020 season.
READ MORE: Houston Texans fire Bill O'Brien after 4th straight loss
I knew this day would come but did not think today. I thought after the KC game. When that did not happen, I was like he is a lifer. #Texans
— David Nuño (@DavidNunoABC13) October 5, 2020
#Texans fire Bill O'Brien and the Astros catch fire to tie the A's at 3. Wild 15 minutes. #Htown
— Greg Bailey (@GregBailey13) October 5, 2020
****BREAKING****
— Joe Gleason (@joeagleason) October 5, 2020
Bill O'Brien FIRED
Thank you FINALLY
— Jose Vela (@JVelaFX) October 5, 2020
After assuming the role of general manager in the offseason, O'Brien received almost universal criticism when he shipped superstar receiver DeAndre Hopkins to Arizona for running back David Johnson and draft picks.
The pressure on O'Brien only intensified as the Texans limped out to the terrible start and Johnson struggled. Their running game was the worst in the NFL and the defense allowed the most yards in the league.

As for social media, many frustrated fans rejoiced and even made Bill O'Brien a trending topic on Twitter.
Bill O’Brien traded the best receiver in the NFL because of a personal feud and then started the season 0-4 and got fired. So Houston lost Deandre Hopkins for personal embarrassment and nothing else.
— Roosh (@RooshWilliams) October 5, 2020
Being a Texans “fan” is an elite level of pain.
BILL O’BRIEN HAS BEEN FIRED pic.twitter.com/7URhnokly3
— Adam Abramson (@Adam_Abramson1) October 5, 2020
A Texans loss and Bill O’Brien getting fired would be the best thing ever happen to Deshaun Watson
— Eric Rosenthal (@ericsports) October 4, 2020
After reports surfaced in the afternoon, the Texans offered a statement confirming O'Brien was let go and Romeo Crennel, the team's assistant head coach, was appointed as the interim head coach.
A statement from Cal McNair. pic.twitter.com/5JbZylPTbp
— Houston Texans (@HoustonTexans) October 5, 2020
Here are some of the top reactions posted on social media.
MERCI @HoustonTexans
— Fire Bill O Brien (@liphbn) October 5, 2020
I forgot bill o brien fumbled clowney too lol god why was he given so many chances to ruin the franchise. I wish Deshaun could walk and go somewhere worth his talent
— JSF (@JSFonYT) October 5, 2020
I’m happy for Texans fans! Really! #billobrien is fired!
— Blake Lawrence (@Blakelaw90) October 5, 2020
Several years too late but we'll take it. #FireBillOBrien #HoustonTexans #ThankYouCalMcNair #billobrien #Texans #NFL Several years too late but we'll take it. https://t.co/kcj7sV6BhK
— Terry Abbott (@TerryAbbott) October 5, 2020
#WeAreTexans Let go Romeo #billobrien https://t.co/zxVvvZwYYg pic.twitter.com/iee1FkcDLF
— Gregory Bishop (@gregoryl1717) October 5, 2020
The Associated Press contributed to this report.