"Happened right in front of the patio where I was sitting in front of Neds," James William described on Facebook in a public post. "He tried to go into the bar but did not make it through the door. Someone took the gun from him and he got shot and is dead."
Graham Hunter, 24, of Dayton arrived in the bar area with four friends as the shooting ended.
"Everyone was panicking and running around," Hunter told CNN. "After the shooter was dead, everyone was just crying and stuff," and he saw "bodies all over the place," including the shooter.
Hunter described the entertainment district as a "nice spot" and where everyone goes to hang out."
The mayor said the Oregon District will reopen Sunday afternoon though the bar will remain closed.
"We are shaken and confused as to why this occurred in our safe entertainment district located in downtown Dayton," Ned Peppers, a "traditional western-ish themed bar," posted on its website. "We have police regularly staffed next to our business who engaged the shooter and neutralized the threat.
"Dayton Police could not have done a better job responding to this senseless act of violence."
The Convention Center is being used for family members and friends disconnected from their family members and friends during the shooting.
The may said 15 of the 27 treated patients at various hospitals have been released
Miami Valley Hospital, which is near the shooting scene, received 14 patients, communications department Terrea Little told CNN. Two others across its health system were treated, Dr. Randy Marriott said.
Kettering Health Network, which operates several Dayton area hospitals, including Kettering Medical Center and Grandview Medical Center, treated around a dozen patients, many with gunshot wounds to the "lower extremities," Elizabeth Long, a spokeswoman, told CNN.
Gov. Mike DeWine posted on Twitter that his wife "Fran and I are absolutely heartbroken over the horrible attack that occurred this morning in Dayton. We join those across Ohio and this country in offering our prayers to victims and their families."
He said the Ohio Department of Public Safety and the Ohio State Highway Patrol offered assistance to local law enforcement "as they investigate this heinous act.
DeWine spoke with President Donald Trump on Sunday morning. They separately ordered flags at half staff in all Ohio state buildings, federal government buildings, military installations and vessels, and facilities abroad through Thursday at sunset. Trump's order simultaneously honors the victims of the shooting in El Paso.
Trump referenced both tragedies in Twitter posts.
"God bless the people of El Paso Texas. God bless the people of Dayton, Ohio."
Minutes earlier he posted: "The FBI, local and state law enforcement are working together in El Paso and in Dayton, Ohio Information is rapidly being accumulated in Dayton. Much has already be learned in El Paso. Law enforcement was very rapid in both instances. Updates will be given throughout the day!"
On May 27, several tornadoes touched down in Dayton and surrounding communities, damaging buildings and causing one death.
"Our community has shown incredible resilience in the face of these tragedies, and I'm sure Dayton will rise to this challenge as we always have," he mayor said in a statement posted on Facebook.
"We have suffered two tragedies in Dayton this year, but one was avoidable. This same tragedy has been inflicted on our nation 250 times this year alone. When is enough, enough?"