Last minute site evaluations can save a life and your piece of mind, according to this month's Practical Management with Paul Ridilla.
Our insurance companies call their after-hour liability an "attractive nuisance," but my order to all of our jobsite foremen is, "Eliminate any possible kid killer." We require them to walk their entire work area to evaluate any potential danger a child or adult might encounter if they were on that site after work hours. You cannot go home from that jobsite and merely assume no one will be there that night, especially over a weekend. What I really emphasize is for them to remember when they were children and imagine all they would have done or tried to do. That usually gets my message across!
Our liability results from the fact that we created that potential hazard, or attractive nuisance. Merely putting up NO TRESPASSING signs does not relieve us of liability since some small children cannot read, and someone could enter your site without seeing your signs. Keep in mind it could be after dark.