Just did the latest firmware update and it failed at about the 75% mark. Drone is now bricked and won't turn on. What do I do now?

We are sorry to know the unfortunate event that happened with the drone. Can you try to charge the drone's battery and check if it is working? If so, please try again to power the drone once the battery is full. Please be advised that during firmware updates, the drone turns off automatically due to overheating. While restarting the drone, it will be configured to automatically updated again. If you are using a DJI RC, it may show a “Firmware update failed” warning. However, if the troubleshooting steps are done and if the drone still can't be powered on, we suggest sending the drone to our facility for a proper diagnosis. Please contact our relevant team using this link https://www.dji.com/support for further assistance at the request. Hope this helps. Thank you.