Hi

Today I try myTello and when do 360 android app stop working. Tello start slideing toward kids. I try to catch from lower part of drone but fly higher. After that is took it from propeller guard. Saved kids but drone try flying and spin up propellers. I hold with two hands and try to stop but cut my fingers. Other ppl helped to power off.

How can I emergency stop this drone without controller?

I believe the tello is like many others and if you have it in your hand turn it upside down or angle and it should shut off.  also the sensors on bottom of it will raise it if it sees your hand so got to be kind of fast if catching it.

If you can't hold down the left throttle virtual stick on the phone (which puts Tello in landing mode when it comes down and automatically powers off), you can power off the Tello like other DJI drones by grabbing hold of it and turning it to either side by 90 degrees.