Complex sentence: The creature tries to find the brakes to try and stop the train, but fails to even get it to slow down as it rams through the barrier and plunges down the cliff, destroying it as soon as it hits the bottom.
Split into simpler sentences: The creature tries to find the brakes to try and stop the train, but fails to even get it to slow down. The train rams through the barrier and plunges down the cliff and is destroyed as soon as it hits the bottom.