They start arriving before sunrise and stay until well after nightfall, hoping to donate blood or their time or anything to soften the tragedy that has engulfed Las Vegas.

It has been more than two days since a gunman – identified as Stephen Paddock – killed 58 people enjoying a concert, and still a line of blood donors stretches down the street.

At a branch of United Blood Services, where the glittering Las Vegas Strip gives way to sun-baked malls, dozens waited for the doors to open at 9am.

“The events of Sunday just reminded me how valuable this is”, said 62-year-old architect Brian Grill, adding that it has been 20 years since he last donated blood. “There wasn’t a lot I could do, but this is one of things I can do”.

They are waiting to be put on a list, hoping to snag one of 120 standby spots. Appointments are booked through to mid-November.

“It’s been overwhelming in terms of the community support,” said Phillip Hollon of the Salvation Army, which is helping to co-ordinate logistics. “They want to do something. They don’t want to just sit home and watch TV”.

Las Vegas shooting – in pictures Show all 15 1 /15 Las Vegas shooting – in pictures Las Vegas shooting – in pictures People scramble for shelter at the Route 91 Harvest country music festival after gun fire was heard Getty Las Vegas shooting – in pictures People carry a person at the Route 91 Harvest country music festival after shots were fired David Becker/Getty Las Vegas shooting – in pictures People run from the Route 91 Harvest country music festival after gun fire was heard David Becker/Getty Las Vegas shooting – in pictures A handout photo released via Twitter by Eiki Hrafnsson (@EirikurH) showing concertgoers running away from the scene (C) after shots range out at the Route 91 Harvest festival on Las Vegas Boulevard EPA/Eiki Hrafnsson Las Vegas shooting – in pictures People lie on the ground at the Route 91 Harvest country music festival after hearing gun fire Getty Las Vegas shooting – in pictures A man in a wheelchair is taken away from the Route 91 Harvest country music festival after hearing gun fire David Becker/Getty Las Vegas shooting – in pictures People stand on the street outside the Mandalay Bay hotel near the scene of the Route 91 Harvest festival on Las Vegas Boulevard EPA/Paul Buck Las Vegas shooting – in pictures FBI agents confer in front of the Tropicana hotel-casino after a mass shooting during a music festival on the Las Vegas Strip Reuters/Las Vegas Sun/Steve Marcus Las Vegas shooting – in pictures Las Vegas police run by a banner on the fence at the Route 91 Harvest country music festival grounds after shots were fired David Becker/Getty Las Vegas shooting – in pictures An injured person is tended to in the intersection of Tropicana Ave. and Las Vegas Boulevard after a mass shooting at a country music festival Ethan Miller/Getty Las Vegas shooting – in pictures Metro Police officers pass by the front of the Tropicana hotel-casino after a mass shooting at a music festival on the Las Vegas Strip Reuters/Las Vegas Sun/Steve Marcus Las Vegas shooting – in pictures A woman sits on a curb at the scene of a shooting outside of a music festival along the Las Vegas Strip AP/John Locher Las Vegas shooting – in pictures A cowboy hat lays in the street after shots were fired near a country music festival in Las Vegas Getty Las Vegas shooting – in pictures Las Vegas Metro Police and medical workers stage in the intersection of Tropicana Avenue and Las Vegas Boulevard South after a mass shooting at a music festival on the Las Vegas Strip Reuters/Las Vegas Sun/Steve Marcus Las Vegas shooting – in pictures Sheriff Joe Lombardo (2-R) speaking during a press briefing in the aftermath of the active shooter incident on Las Vegas Boulevard EPA

Bryan Dredla was here at 6am yesterday. His turn to give blood didn’t arrive until 9pm at night. He is back again today, volunteering, saying he is willing to stay for days and offer “as much as they need”.

“It sucks that it takes a tragedy to have this kind of community,” said Mr Dredla, who is 26, “but it’s really refreshing.”

Reinforcements have poured in from large chains and small mom-and-pop businesses – 30 to 40 of them in total – who have furnished waiting donors with free coffee and pizza and sandwiches. A local insurance business sent 100 breakfast burritos. A man setting up to grill hot dogs said he brought his equipment out of the garage where it has been gathering dust since he retired from vending in 2009.

“In a situation like this, people should come together and try to help each other,” said 68-year-old Henry Bryant.

Body cam footage shows officers during Las Vegas mass shooting

Organisers marvelled at both the scope of the turnout and how far people have travelled. Some have driven in from other states; three people flew out from New York.

“We all have been getting about three hours of sleep a night” trying to stay on to of it, Mr Hollon said.

Displays like this have been a source of pride for Las Vegas as the community rallies to respond to the worst mass shooting in American history.

Stories are everywhere. Javier Wong, a restaurant worker who moved to Las Vegas from Panama 25 years ago, waited more than eight hours to give blood at another location. He said he saw it as a way to support the victims the way his adopted home had supported him.

“I’m giving back,” Mr Wong said.

Elected officials have offered both praise and a measure of apology for the hours-long waits.