Tragedy has struck an Ariana Grande concert in Manchester, England.
According to multiple news outlets, at least 22 people were killed and countless others injured after a pair of loud bangs were heard Monday evening inside Manchester Arena.
Law enforcement sources in Great Britain and the United States have told NBC News they believe these sounds to have been explosions.
Shortly after reports started to leak out about what transpired or may have transpired at the concert, Greater Manchester Police confirmed there were a "number of fatalities and others injured."
It remains unclear just how many people died from the explosions themselves and how many were killed as a result of the stampede that occurred after the blasts went off.
Those associated with the event tell TMZ they heard an explosion in the rotunda area (where merchandise is sold), which is located outside the seating area in the venue.
Immediately afterward, mass chaos ensued as everyone sprinted toward the nearest exit.
About two hours after outlets starting reporting on the horrible occurrence, police said they were treating it as a terrorist act.
There are reports the explosive device was a "nail bomb," TMZ writes, which would explain why many victims at the scene were bleeding profusely.
"Ariana is okay," a representative for the artist says.
"We are further investigating what happened."
Manchester Arena sits atop the Manchester Victoria transit station. As of this writing, all lines to Manchester Victoria were closed, National Rail says in a statement.
Northern Railway said the station had been evacuated and local police have issued the following statement:
“Emergency services are currently responding to reports of an explosion at Manchester Arena. There are a number of confirmed fatalities and others injured.
"Please avoid the area as first responders work tirelessly at the scene.
"Details of casualty bureau will follow as soon as possible.”
This is what a concert goer told The Daily Mail of what he witnessed after the first explosion went off:
"Everybody started screaming and running for the exit ... We could hear the police and ambulance sirens. It was terrifying.
"There were thousands of people trying to get out at once. They were all screaming and crying. The whole place smelt smokey and burnt."
Added another person in attendance, this time to The Manchester Evening News:
"We saw young girls with blood on them, everyone was screaming and people were running."
Victoria Monét and Bia opened for Grande on Monday night and both artists are believed to be fine.
Grande’s tour was scheduled to continue at the O2 Arena in London on Thursday night, but it’s hard to believe this show will now take place.
Not that it matters at the moment, of course.
The Manchester Arena, which opened in 1995, can hold up to 21,000 spectators; it was not clear how many people were in the crowd for the concert.
But it is clear that this is a tragedy of massive proportions.
UPDATE: We've found a video that purports to show the explosion.
Look to the left in the following footage and listen for a loud bang:
Said another witness to the BBC:
"The lights had come up everyone was just getting out and walking towards the stairs, when all of a sudden this huge sound which sounded like an explosion went off."
"Everyone just stopped and turned around."
"Then somebody shouted 'it’s a bomb' and everyone just started running. Everybody was trying to push people up the stairs."
"There was a lot of children there without parents. There was no one to calm them down so everyone was just screaming crying and pushing."
How awful. Simply awful and absolutely unimaginable.
Our thoughts go out to the victims of this attack, and we will continue to update this tragic story as more information becomes available.
Update: This is the latest string of Tweets from the local police department whose officials are investigating the violence:
Update: Grande has suspended the remainder of her European tour until an unspecified date, while the death roll has risen to 22.
At least 59 people are injured, 19 of them in critical condition.
Police are treating this as the act of a suicide bomber, presuming the attacker is dead, but investigating whether or not he was part of a larger organization/network.
And Grande has Tweeted the following statement:
UPDATE: Salman Abedi has been identified as the bomber.