This morning, America woke up to the deadliest mass shooting in its modern history, with at least 50 killed and hundreds more wounded by James Paddock, a 64-year-old Nevada retiree who fired on a country music festival from his hotel room in the Mandala Bay.

There are a lot important questions that need to be asked about the United States’ horrifying and unique issues with gun violence, but there is an even more immediate and desperate need in Las Vegas for blood donors. Doctors and medical professionals are rushing to save the lives of those wounded by the gunman and in the mad rush to escape, and local blood banks do not currently have enough blood on hand to meet the need. If you live in Las Vegas or the surrounding areas, here are places currently accepting your donations.

Even if you don’t live near Vegas, sharing the need for blood donations on social media can help spread the word. It’s a small way to help, but it can save lives. Also, remember that blood banks do occasionally turn away potential donors in the immediate aftermath of a tragedy if too many people show up. If that happens to you, it’s always worth checking back a few days later to see if there is a new need, particularly if you have a rare blood type.