On a hot August afternoon, I finished a call with a client as I opened the door to the room of my 2-year-old daughter, Alice. She’d slept a little longer than usual, and I needed to wake her so we could retrieve my 4-year-old daughter, Grace, from school. I leaned over Alice in her crib, and she was stiff and blue. Bad, bad, very bad ran through my brain. I started CPR, counting two breaths per 30 chest thrusts, and somehow managed to call 911. Eventually, the paramedics arrived. They told me to stand back. I did. Shortly after, I...