More than 30,000 mourners from all parts of Israel gathered at Mount Herzl military cemetery in Jerusalem on Wednesday morning to pay their last respects to “lone soldier” Max Steinberg of Encino, Calif.

A U.S. citizen who volunteered for the Israel Defense Forces, Steinberg was killed early Sunday when a Hamas anti-tank rocket struck his armored personnel carrier, killing him and 6 other soldiers from the Golani brigade.

Mourners joined the Steinberg family—his parents, Stuart and Evie Steinberg; his brother Jake; and his sister Paige—who flew in from Encino, Calif.

Steinberg joined the IDF after participating in a 10-day Birthright trip to Israel with his brother and sister in June 2012. His father told the Los Angeles Daily News that Max had such a positive experience that he returned back to Israel a few months later to live there indefinitely.

When Max became a volunteer in the IDF, he intentionally pursued the Golani brigade—combat troops on the front lines of battle, his father said. When he was initially told his Hebrew was not good enough to qualify, he took time off to immerse himself in the language because he couldn’t imagine doing anything else in the IDF, according to his friends.

“The guys who are willing to go down that road have made some kind of personal choice,” said Stuart Steinberg. “The consequences were horrible. Not in our wildest imagination did we expect this was going to be our experience, but it’s the price of war.”

A Facebook page created to draw participants to the funeral in support of Steinberg and his family read: “Max Steinberg (may his memory be a blessing) died al-Kiddush Hashem (for the sanctification of G‑d’s name) in Gaza sacrificing his life to defend Israel. Max was a lone soldier from Los Angeles. Let’s make sure his extended family here in Israel is there to say goodbye to him and honor his life.”

On Monday, some 20,000 mourners gathered at the funeral in Haifa of Sean Carmeli, a native of Texas, after a similar campaign was launched on Facebook.

Those wishing to show their solidarity with IDF troops can “Write to an IDF Soldier” and dedicate a mitzvah on their behalf here.

Printouts of letters will be hand-delivered to troops in Israel by staff and volunteers from the Chabad Youth Organization of Israel.