Make a puddle of water and put the guest in it. After maybe five seconds, a message will state that they died.
Make a roller coaster or a ride like the Launched Freefall, Inverted Vertical Shuttle, or Powered Launched Coaster. Make a roller coaster that is short of track, set the speed to its highest, and put the waiting time for full load. The coaster will explode and kill all the riders.
In order to kill mass amounts of people, make a ride that many guests will ride, such as A Shuttle Loop Coaster. Put a puddle of water just outside the exit. When they leave the ride, they will fall into the puddle and drown.
Use the following trick to make guests drown in the shape of a cross. Make a path high above water. End the path above the water. One square before the end of the path, make a "Do Not Enter" sign facing the end of the path, trapping the guests. When you have more than thirty quests on that square of path, delete that section. If done correctly, the guests will fall in the shape of a cross or "T."
Start a new game or go to the custom roller coaster designer. Make a LIM Launch Coaster and have the track go up in a regular incline to a desired point. Next, make a loop and a helix down (small). End the track there. Set the launch speed to 69 mph. Make the waiting a full load, then watch as the car goes up in flames. You can also do the same thing with a looping roller coaster. If possible, make it like the shuttle loop from Roller Coaster Tycoon. Set the speed to an amount so that the coaster will not fly off the top. Finally, watch it come down on a crowd of people.
Use the following hint to kill guests without losing your rating. To get this to work, you need a path going underground, however long you desire. First, stop guests from leaving the path by putting up no entry signs outside of the start of the path. Get the amount of people you wish on that path then delete it. The guests will fall for around ten seconds, then they will disappear. They will be no longer counted on your guest total. This trick is useful when your other guests think that it is too crowded.
Place a footpath on a body of water, then wait until a group of guests are on the same path square. Delete the path square. The guests will fall into the water and drown.