A driverless Waymo vehicle ensnared itself in wet cementÂ

On Friday morning, a driverless Waymo vehicle, for reasons unknown, rolled into a patch of wet cement on the grounds of Laguna Honda Hospital and sank in. It was, for onlookers, a source of much mirth and cellphone picture-taking. 

A witness tells your humble narrator that the wet cement ought to have been better demarcated with barricades — but, also, that a human driver would never, ever have made this mistake.