Complex sentence: By summer 1934 Hindenburg was dying of metastasized bladder cancer and his correspondence was dominated by complaints of Nazi storm troopers running amok, so Hindenburg asked Hitler to rein them in.
Split into simpler sentences: By summer 1934 Hindenburg was dying of metastasized bladder cancer. His correspondence was dominated by complaints of Nazi storm troopers running amok, so Hindenburg asked Hitler to rein them in.