Sorry for the loss. Have you had a drone before? Flying that far away in a heavily urban area is very risky. You likely had significant radio interference which was causing the drone to get nefarious commands. It is not an exclusive radio frequency although it is proprietary between the unit and controller. I also strongly doubt you kept visual Sight of your drone or even line of sight as you were over 1.5 miles out. Once you lose line of sight, all bets are off. I noticed you went well over 400 feet? Obviously you turned off your limits. What other major settings did you change? If you find it, don't break rule one or two (visual and line of sight) in a heavily urban area and you will have better results. Bummer.
Yes, this is not my first drone, im pretty experienced with them, I admit I was perhaps pushing it to its limits but I thought I was still well within them. I had 18 satellites and strong connection with the drone. The 'incident' happened with almost no warning and by the time it did, there was nothing I could do to pull it out. Went door to door in the area again this morning with no luck.