Complex sentence: Emergency responders found Prince unresponsive in an elevator and performed CPR, but were unable to revive him; he was pronounced dead at 10:07 a.m. He was 57 years old.
Split into simpler sentences: Emergency responders found Prince unresponsive in an elevator. Prince did not respond to CPR administered by emergency responders and was pronounced dead at 10:07 a.m. He was 57 years old.