One Direction fans were devastated when the announcement was made earlier that their much-awaited concert has been canceled.

Louis Tomlinson, Harry Styles and Niall Horan knew how much the concert matters to their die-hard fans, so these One Direction members took to Twitter to apologize for the unfortunate event.

Styles tweeted how sorry he was and expressed his disappointment about the canceled concert.

Tomlinson posted his own apology seven minutes after his band mate's tweet, saying it went out of control and thanked the fans for understanding Liam Payne's current situation.

An hour after Styles and Tomlinson's post, Horan tweeted asking for an apology, stating that unfortunate things like this happen and thanked the fans for coming.

One Direction's concert in Belfast, Ireland was canceled because Payne suddenly became sick. Here's a video recorded by 1D Updates, which was uploaded on Twitter, announcing the cancelation of the band's concert.

#Video Tonight's announcement about the show being cancelled pic.twitter.com/c2sPN66ArH

— 1D Updates (@WW1DUpdates) October 20, 2015

This is the first One Direction show in five years that has been canceled, so many are thinking the incident is quite serious, according to Teen Vogue. One Twitter post seems to support this report.

The post stated that One Direction didn't cancel a concert when they were ill or had broken bones. They didn't cancel when Styles had an angina nor when Zayn Malik left the band.

Many One Direction fans were disappointed. However, most were just concerned about Payne's condition, and not knowing what actually happened caused hysteria among fans.

There are speculations that one of the "Drag Me Down" singers was hospitalized, but no official statements were released yet. For the meantime, the worried supporters are flooding Twitter with messages, sending their love and support to the band's sick member, wishing him to get well soon.

Some reports say that 45 minutes after the concert cancellation was announced, the hashtag #GetWellSoonLiam reportedly trended worldwide on social media sites.

The scheduled show was attended by thousands of One Direction fans. As per the report of Seventeen, some of them have travelled from Greece and France and others have waited in line since the break of dawn.

The organizers advised the fans to hold on to their tickets because updates will be provided soon.

2015 is rather an overwhelming year for One Direction fans, with Malik leaving the group, the British band going on an indefinite break after their "On the Road Again" tour, and now, this canceled concert.

Many are still hopeful that everything will fall into place soon.