Thousands of fans streamed out of a concert by US pop star Ariana Grande, in the English city of Manchester, when a suicide bomber struck, killing at least 22 people and wounding 59 others.
Prime Minister Theresa May said the incident was being treated as a terrorist attack, making it the deadliest such assault in Britain since four British extremists killed 52 people in suicide bombings on London's transport system in July 2005.
As feelings of horror and grief took over Manchester, the city displayed its true Mancunian spirit.
#RoomForManchester began to trend on Twitter with locals coming together and offering shelter to those affected by the blasts.
If you need a bed, a cup of tea, a charged phone etc. - I'm 15 mins from Manchester Arena. DM me, they're open! #RoomForManchester— Rachel Ellis (@rachelkellis) May 22, 2017
Mayor of Greater Manchester, Andy Burnham, also took to Twitter to express his condolences. He tweeted out the #RoomForMAnchester and #MissingInManchester, urging people to come out and help in all ways possible.
One of the Twitter users said, " If someone needs a place to stay in Manchester let me know. Have room for a few and safe and sound. Pray for those not as lucky."
People were seen looking for their missing loved ones and children after the blast. Many turned to social media to seek help.
Another user tweeted, "Everyone pls share this, my little sister Emma was at the Ari concert tonight in #Manchester and she isn't answering her phone, pls help me," alongside a picture of a blonde-haired girl with flowers in her hair.
Paula Robinson, 48, was at the train station next to the arena with her husband when she felt the explosion and saw dozens of teenage girls screaming and running away from the arena.
"We ran out," she told Reuters. "It was literally seconds after the explosion. I got the teens to run with me." Robinson said she took dozens of teenage girls to the nearby Holiday Inn Express hotel and tweeted out her phone number to worried parents telling them to meet her there. She said her phone had not stopped ringing since her tweet.
However, there was some confusion about which hotel she meant. Holiday Inn later issued a statement, saying it did not take in concert-goers.
From free taxi rides to phone chargers and cups of tea, people were there to help the affected get in touch with their families and loved ones.
For customers who are in Manchester now if any one needs to come back to Bury just call us taxi for free— Elton Bullitt Taxis (@EltonBullitt) May 23, 2017
Social media was also useful in dispersing information regarding medical help.