(NEWSER) – Sunday morning’s bloodbath at Pulse Orlando nightclub was far bloodier than police initially indicated, with the city mayor now confirming at least 50 casualties in what is now the worst mass shooting in American history, reports the AP. At least 53 people have been hospitalized. “There’s blood everywhere,” Mayor Buddy Dyer told a news conference.

The gunman has been identified as Omar Mateen of Port St. Lucie, Fla., an American citizen born to Afghan parents, reports ABC News, which characterizes Mateen as “on the radar” of authorities, though not on a specific watchlist or subject of an investigation. “It appears he was organized and well-prepared,” Orlando’s police chief tells CNN, adding that Mateen had an assault weapon, handgun, and “some type of (other) device on him.” Florida Gov. Rick Scott is en route to the scene and says in a statement that “We will devote every resource available to assist with the shooting in Orlando.”

This incident follows the fatal Friday shooting of 22-year-old singer Christina Grimmie, who was killed after her Orlando concert at Plaza Live by a 27-year-old Florida man who later killed himself. The two venues are less than four miles away from each other and the two shootings do not seem to be related.