This afternoon I took my car to Mt. Wilson for a pleasure ride. Leaving home with 80% charge (daily full charge), arriving at 50% charge. Both car and phone lost internet connection there. Heavy fog turned into light rain. Spent two hours in observatory. When I was ready to leave, the doors won't pop when I got close. Touching the door handle won't pop it out. I started panic: It shouldn't lose all the battery juice in just two hours, even though it's raining it's not that cold. Hitting key fob for opening door, frunk and truck; none worked. Took a ride back down to La Canada and call roadside assistance from McDonald's. They can connect to car and remotely open the door but I need to be there. I was also told if someone else has the app, they can open the door for me as well. It's getting dark, so I took a Lyft home and plan to take care of it tomorrow. Just now installed the Tesla app on wife's iPad, so she can help me remotely open the door as backup tomorrow in addition to the assistance from Tesla. I need to understand why this is happening so it won't happen again. I will research into this topic, but hopeful I may get some insight from you guys out there. Why the key fob is not working? Is it because lack of cellular connection for either or both of car and phone? How to prevent this inconvenient breakdown from happening again in future? I recall now that I once read about putting key fob near windshield if everything else failed. Too bad I did not think of this and gave it a try. I was able to connect phone app with the car at home, even though according roadside assistance staff the signal from car is in and out not steady. It does show car still has 50% charge. Key fob should have enough battery since I only received the car for little over 5 weeks ago.