How to Obtain the Chain Reaction Achievement in "GTA IV"

Getting the Chain Reaction achievement requires you to destroy 10 vehicles in 10 seconds. By using a bus and a bridge, you can quickly stockpile enough cars in a cramped location to obtain the achievement and get 20 gamer points. Just add an explosive device and watch the flames.

Instructions

1. Steal a bus. A prime location for finding parked buses is alongside the streets of Star Junction in Algonquin. You should choose this location not only for its abundance of buses, but because it is nearest a bridge.

2. Drive to a bridge. Take the bus to the Algonquin-Dukes Bridge (or the closest bridge if you stole your bus from another location). Drive on the left side of the bridge so that traffic is coming toward you.

3. Block traffic using the bus as a barricade. Once you are able to see cars coming toward you in the distance, immediately press the “A” button to activate the emergency brake and quickly turn the bus so that it is blocking both lanes of the oncoming traffic.

4. Climb onto the roof of the bus. Exit the bus and jump onto the hood of one of the vehicles that has stopped at the front of the pile. You will be able to safely explode the vehicles from this vantage point.

5. Use the grenade launcher or toss grenades into the pile of cars. Wait for at least twelve vehicles to pile up before you start pumping out explosives. This will ensure that you get enough explosions to obtain the achievement. Try to begin the explosions in the rear of the pile, working your way up to the front.

6. Destroy the bus. Before the cars nearest you explode, jump off of the roof of the bus, and run away. Once you are a safe distance away from the explosions and the bus, quickly shoot the bus with the grenade launcher. All of the vehicles should soon be destroyed and you will obtain the achievement.

Tips & Warnings

• Using the grenade launcher as opposed to tossing out grenades will yield quicker, more accurate explosions.

• If you have Kiki as one of your girlfriends, you can look her up on your cell phone to clear your wanted level after you have caused the explosions.