Thanks for your comments everyone, and I enjoyed hearing your stories! I know he's an adult, but I still am concerned! You helped me through an anxious time.
DS finally got to his apartment at 5:20 a.m. his time. He was supposed to get in at 11:30 p.m. His last plane was delayed 3 times. He said he slept on the plane for a few hours and slept about an hour when he got home before going to work. I texted him earlier to see how he was doing, and he called back a while ago.
He's heading to the movies with some of his work friends. No taking a nap! Oh to be in my early 20's again and have energy! 