Keep flammable and volatile liquids capped and out of the reach of little ones. If containers are not tightly closed, vapors may escape that can be toxic when inhaled. Also keep them away from ignition sources. The Consumer Product Safety Commission has documented several cases in which gas stored as far as 10 feet from a water heater exploded. And not just in big pools, but also wading pools and even coolers.
Some jurisdictions outlaw diving boards.
Most problems with pools involve guests who don't see the risk. Slides, swings, ropes, even covers all have liability built into them. Since 1993, federal regulations mandate that all automatic door openers be equipped with a non-contact invisible beam system. If a person, animal or object breaks the beam as the door is operating, the door reverses and goes back to the open position. Some like it hot, but guests who are not used to 140-degree water can easily be burned.