As of now, ET can confirm that Odom's estranged wife Khloe and her sisters, Kim, Kourtney and Kendall Jenner, have touched down in Las Vegas. The mother of Odom's children, Liza Morales, arrived as well, along with their daughter Destiny, son Lamar, Jr., and Odom's aunt JaNean.
"They are devastated. They have tried so hard to help Lamar with his issues and it breaks their hearts that he could lose this battle," a source close to the family told ET on Wednesday. "The entire family is pulling for Lamar to make it through this."