Metro Expo Line Westwood Blvd track installation -- part 1

This is a video of at-grade rail crossing installation across Westwood Blvd by Exposition Blvd for the light-rail Metro Expo Line Phase 2 to Santa Monica, California, in Los Angeles County.
Westwood Blvd is being closed from 9 pm Friday to 6 am Monday and the work will be finished by day and night work within this period. The first step was to excavate the road. Then subballast (fine gravel) and ballast (coarse gravel) was spread and rail ties (sleepers) were placed every two feet. Rail is being installed with the help of heavy machinery. You can see a ballast regulator, a ballast tamper, and a large crane in the background to place these two heavy machines on the tracks. Ballast regulator shapes the ballast and ballast tamper adjusts the horizontal and vertical positions of the rails. Once this is finished, at-grade-crossing panels will permanently cover between the rails for the cars to be able to drive over.
What's really peculiar is the sound that comes off the rail when it's hit by a heavy metal object, such as the hook of the lifter. It resonates and produces a very unique sound, like a sound effect in a sci-fi movie -- I am thinking about James Cameron's The Abyss I think.