rosrun tf2_tools not found

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In the very first tutorial of tf2, we run the command rosrun tf2_tools view_frames.py. I tried this on two different systems running Ubuntu 16.04 and ROS kinetic. On both systems, I get the error [rospack] Error: package 'tf2_tools' not found. I built my workspace using catkin_make and sourced my workspace. the ros master is running and I followed all tutorials exactly. rospack find tf2_tools yields the same error, but tf2 itself can be found. Any ideas why this is failing?