Grand Theft Auto: San Andreas/Explosive Situation

At the quarry, get into the dump truck and crash into each box of explosives and get out to retrieve each. Deal with the quarry workers if they get annoying. After getting the explosives, security attempts to block the exit. Grab the Sanchez and meet each marker by going up the spouts and machinery. Avoid security and head back to the drop point with the explosives.

Tips
You can stop the clock by taking out the two guys near the Plunger (or just the guy with the beard). You can then use the truck to break the boxes before grabbing the dynamite with the Sanchez and making your escape. You even won't have to use the Sanchez and the ramps, to escape. Just walk or drive the Sanchez near the gate, snipe the four security guards, then drive on their cars in front of the gate, jump at the car and then you are outside.

Rewards

 * Cash: $7,000
 * Respect +
 * Quarry Missions unlocked.
 * Casino Heist Missions unlocked.