Sept. 5, 2019—Tesla's app underwent an outage this week that left some Tesla owners stranded, according to CNET.
The app was down for about four hours on Monday evening. Owners went to Twitter asking Tesla for assistance as the app was their only way of unlocking and starting the car.
Tesla, however, issues a backup key card for all owners to use in case of an emergency. The card sits tidy in a wallet, but it appears not many owners keep the card on them, per some of the tweets.