As the nation tries to come to terms with the horrors of last night's mass shooting at Bondi Beach, countless Australians are stepping forward to help.
Lifeblood Australia's website crashed because of the sheer number of people trying to find out where they could donate blood.
Its Sydney centre had lines snaking out the door and down the block this morning as hundreds turned up to donate.
LIVE UPDATES: Gunmen were father and son; Sixteen people dead, more injured in Bondi Beach shooting
Vigils are being planned for the 15 innocents killed in the horrific attack, and police are calling members of the public to share valuable information.
Here's how everyday Australians can help in the wake of the Bondi Beach shooting.
Donate blood or plasma
Lifeblood issued an urgent callout for blood donations, especially type O negative (the universal donor type), in the wake of the attack.
Eligible Australians can donate blood, plasma, or platelets at a Lifeblood donor centre.
You can find your nearest centre here.
Donors must meet certain eligibility criteria. You can check your eligibility here.
READ MORE: What we know about the two Bondi Beach gunmen
Donating blood takes about 10 minutes, with a one-hour appointment time.
Plasma takes about 45 minutes to donate, with a total appointment time of one and a half hours.
Donating platelets takes around an hour, with a total appointment time of two hours.
People are asked to be patient with the long lines.
Bondi Beach shooting vigils
A memorial site has been established at the back of Bondi Pavillion, where the pile of flowers and other tributes is growing.
Vigils have already been held around the world for the shooting victims, including in the US, UK and parts of Europe.
More vigils are expected to be held in Bondi and around the country in the coming days.
A healing ceremony with the Indigenous community will be held in the centre of Sydney tonight.
The event is at 5.30pm at Hyde Park.
"As Indigenous people we hold a responsibility to safe guard, nurture and send love," Vanessa Turnbull Roberts said.
"It's who we are, who we have all been.
"This shooting took place on a land that was not the first time to have this happen."
READ MORE: 'Daddy, what is that?': Family forced to run for their lives as Bondi shooting began
Online condolence book
The NSW government has set up an online condolence book for people to leave messages of condolence in the wake of the attack.
You can send a message of condolence on the official NSW government website here.
Support for Australia's Jewish community
Prime Minister Anthony Albanese has urged Australians to show support for the nation's Jewish community.
The Jewish Council of Australia encouraged Aussies to stand with the Jewish community by lighting a candle in a window at 6.47pm on Monday night.
The gesture honours the festival of Hanukkah, an annual Jewish celebration of light and miracles.
Albanese and local member for Wentworth, Allegra Spender, backed the gesture and urged Aussies to reach out to members of local Jewish communities.
"The Jewish community are hurting today," Albanese said.
"Today, all Australians wrap our arms around them and say, 'we stand with you.'"
READ MORE: Rabbi and French citizen identified as victims of Bondi Beach shooting attack
How to help police
Anyone with information about the incident is urged to contact Crime Stoppers on 1800 333 000 or online here.
Information is managed on a confidential basis.
NSW Police are appealing for anyone with mobile phone or dashcam footage relevant to the Bondi shooting to send it directly to police.
You can submit video evidence to police through the NSW Police Force Evidence Submission Portal here.
Witnesses of the shooting are also being urged to attend a community reception centre in Coogee and speak to investigators.
The centre has been established at the InterContinental Sydney Coogee Beach, 242 Arden Street, Coogee NSW 2034.
If you have been impacted by the terror attack in Bondi there is support available.
To contact Lifeline Australia, call 13 11 14 or text 0477 13 11 14. For people under 25 years old, you can contact Kids Helpline at 1800 55 1800. Both of these are available on a 24/7 basis. If you wish to donate blood, you can find your nearest donor centre here.
DOWNLOAD THE 9NEWS APP: Stay across all the latest in breaking news, sport, politics and the weather via our news app and get notifications sent straight to your smartphone. Available on the Apple App Store and Google Play.