Last Friday afternoon in Federal Way, utility workers came across a manhole that refused to stay closed. Meter readers with Lakehaven Utility District first noticed the sewer cover left ajar. They pushed it shut. Later in the day — twice — workers found the manhole open again. The third time, the meter readers had had enough, summoning the Lakehaven sewer crew, who decided to investigate how a 80-pound metal slab could behave like a screen door with a busted latch. What the crew found was even stranger.