Complex sentence: On September 12,2016, the Rams played their first regular season game since returning to Los Angeles, where they lost to the San Francisco 49ers 28-0 at Levi's Stadium.
Split into simpler sentences: On September 12,2016, the Rams played their first regular season game since returning to Los Angeles. They lost to the San Francisco 49ers 28-0 at Levi's Stadium.