The latest episode of the Channel 4 show saw Hassan's popular character Lynsey Nolan found dead in a top-secret storyline twist.
A number of Hassan's closest Hollyoaks friends today spoke exclusively to Digital Spy about her exit, tipping the actress for a bright future.
Jeff Rawle, who plays Lynsey's evil nemesis Silas Blissett, commented: "I would just like to say how brilliant it has been working with Karen. She became an exceptional adversary to Silas and it made all the scenes we had together very strong.
"She's a beautiful person and a brilliant actor. I know everyone on Hollyoaks is really sad to see her go. I hope we get to work on something together again soon."
Bronagh Waugh, better known as Lynsey's best friend Cheryl Brady, said: "Karen and I began our Hollyoaks journey together back in 2008 in Laters. She is a phenomenal actress who always manages to make the audience laugh and cry in equal measure.
"I will miss my friend dearly but I know she is starting a new, very exciting chapter in her career. She was always an integral part of the Bradys and our Hollyoaks family. I can't wait to see what she does next as she's a very special actress! Good luck my wee pal - love you always!"
Rob Norbury, who portrays Lynsey's ex-boyfriend Riley Costello, told us: "Karen is the sexiest nurse in soapland! One of the best, most natural and professional actresses I've ever worked with. She is a real laugh a minute and I'm hoping she can get me a little cameo when she one day ends up in Hollywood! Or can at least put me up on the sofa!"
Jessica Fox - Nancy Osborne in the show - explained: "Lynsey Nolan has been at the centre of some of the best storylines over the last two years and will be very much missed. I have no doubt Karen will go on to do great things and I wish her all the best."
Others who voiced their support for Hassan included PJ Brennan (Doug Carter), Emmett Scanlan (Brendan Brady), Claire Cooper (Jacqui McQueen) and Jennifer Metcalfe (Mercedes McQueen).
Brennan said: "Karen is one of a kind, which makes me a lucky person to have met her. I've made a friend for life, but I'll always miss working opposite her and having her great presence on set and around the studio. I'm excited to see her next move onwards and upwards. Just don't forget us Karen!"
Scanlan commented: "Karen and I came into the show together over two years ago. We've danced many times together as Brendan and Lynsey and it's always been charged - it's always been great fun. A girl like Karen will have many more dancing partners to come in the future."
Meanwhile, Cooper explained: "Karen is an amazing friend and to be able to work with someone you get on with on a personal level and respect on a professional level is fantastic. I have so much time for her and she is so generous as an actor, which is all you could ever wish for. She deserves nothing but the best and she'll be sorely missed."
Finally, Metcalfe enthused: "Karen is amazing to work with, she's an absolute pro and a top girl too. It's been brilliant to work so closely with her recently - she'll be greatly missed."
Hollyoaks fans will see the fallout from Lynsey's death play out on screen over the next few weeks.
> 'Hollyoaks' star Karen Hassan chats to Digital Spy about her exit from the show
> Read more 'Hollyoaks' news and spoilers