Don't grill on the deck of your apartment or condo. I know, it seems so convenient to fire up the grill just a few steps from the table, but the deck is one of your escape routes in an emergency. Don't compromise it by putting the grill out there. Once the cooking is done, properly dispose of any used charcoal. Put the coals in to a metal or other non-combustible container well away from the building or anything else that might burn.
Liquid propane is highly flammable and dangerous if it escapes.
Better to keep it bottled up by closing ALL the valves. And, when you take the tank to be refilled, don't forget to plug the opening with that little plastic plug attached to the tank. Water safety is another priority summertime issue. Eighty-four people reportedly drowned in Wisconsin in 1998. Nationally, drowning is the third leading cause of unintentional death in kids 14 and younger.