People are waiting on line for as long as eight hours in Las Vegas to donate blood to the victims of the worst mass shooting by a single gunman in recent U.S. history.
The shooter, identified as 64-year-old Stephen Paddock of Mesquite, Nevada, opened fire on a crowd of more than 22,000 attending a country music show Sunday night before killing himself as police closed in.
Paddock shot from a hotel room on the 32nd floor of the Mandalay Bay Resort and Casino, located across the street from the outdoor concert.
Fifty-nine were killed and 527 wounded.
In Las Vegas, VOA's Elizabeth Lee spoke with a taxi driver who dropped off a passenger minutes before the shooting began.
“I dropped a passenger at the Mandalay Bay (Resort and Casino) like 20 minutes before the shooting happened and I was thinking about getting in line at Mandalay Bay but changed my mind and went to the airport. I did hear, like an automatic gunshot from a distance, but I never thought it would be a gun shooting. (I am) shocked, very shocked,” said Las Vegas taxi driver Tamirat Shiferaw.
WATCH: Sheriff on finding shooter
Clark County, Nevada Sheriff Joe Lombardo says along with the 19 weapons found in the hotel room, 18 more guns, explosives, and thousands of rounds of ammunition were found in Paddock's home in Mesquite.
President Donald Trump led a moment of silence on the South Lawn of the White House, facing the Washington Monument, to remember the victims.
He ordered flags across the country to fly at half staff and will go to Las Vegas Wednesday to meet with first responders and console the victims and their families. The president has called the shooting an “act of pure evil.”
Along with gunshot wounds, others were trampled and hurt trying to climb over fences to get away.
Police and federal investigators still do not have a motive.
“We don't know what his belief system was at this time,” Lombardo said.
WATCH: Trump on shooting
Islamic State is claiming responsibility, saying the gunman was one of its “soldiers” and converted to Islam months ago. The FBI says there is no evidence Paddock was tied to any international terror group.
Investigators say Paddock had a girlfriend, but believe she is in Tokyo and was not involved.
Paddock's brother, Eric, is just as baffled as police by his motive. He said the family is “horrified and bewildered.”
He said his brother was a wealthy man with no known political or religious affiliations, no ties with white supremacists and no history of mental illness.
“Where the hell did he get automatic weapons? He's a guy who lived in a house in Mesquite and drove down and gambled in Las Vegas,” Eric Paddock said.
Eric Paddock also said their father was a bank robber who was at one time on the FBI's most wanted list. The FBI called him psychopathic and dangerous. But that the brothers had no contact with their father.
WATCH: Video footage from scene
Addressing the nation, President Trump thanked Las Vegas police for their sacrifices and quick responses during the “terrible, terrible attack.”
“To the families of the victims we are praying for you and we are here for you and we ask God to help see you through this very dark period...in moments of tragedy and horror America comes together as one and it always has,” Trump said.
White House spokeswoman Sarah Huckabee Sanders was on the verge of tears as she described some of the heroism of those who sacrificed their lives to save others as the bullets rained down.
One off-duty police officer was among those killed, and another two on duty officers were injured, Las Vegas police said in a statement.
As the situation at the Route 91 Harvest Festival concert unfolded, people sought safety in the many hotels that line the popular tourist district. The Las Vegas airport is also in the area, and flights there were temporarily halted.
The U.S. Department of Homeland Security has said that there is “no information to indicate a specific credible threat involving other public venues in the country,” but that additional security may be seen at events and public places.
Country star Jason Aldean was performing on stage at the time of the shooting. Hours later he described it as “horrific.”
“I still don't know what to say but wanted to let everyone know that me and my crew are safe. My thoughts and prayers go out to everyone involved tonight. It hurts my heart that this would happen to anyone who was just coming out to enjoy what should have been a fun night,” he said on Instagram.
U.S. Senator Dean Heller, who represents Nevada, called the shooting a “senseless, horrifying act of violence,” while Nevada Governor Brian Sandoval described it as “tragic and heinous.”
British Prime Minister Theresa May also expressed support, saying Britain's thoughts were with the victims and emergency personnel.
Jeff Seldin contributed to this report
In Photos: Las Vegas Shooting
Las Vegas Shooting
Festival participants react
Other artists who were part of Sunday's main stage lineup at the Route 91 Harvest festival reacted on Twitter.
President sends condolences
U.S. President Donald Trump wrote on Twitter Monday morning: "My warmest condolences and sympathies to the victims and families of the terrible Las Vegas shooting. God bless you!"
Politicians react
U.S. Senator Dean Heller, who represents Nevada, called the shooting a "senseless, horrifying act of violence," while Nevada Governor Brian Sandoval described it as "tragic and heinous."
British Prime Minister Theresa May also expressed support, saying Britain's thoughts were with the victims and emergency personnel.
