It's not everyday you see somebody just drive off the road in the middle of a city, directly into a body of water. Thankfully, the driver managed to get out.
This accident occurred in Chiang Mai, a city in northern Thailand, and as you can hear, the person behind the wheel of the dashcam car was properly shocked to see what was happening.
According to the description of the video, why the pickup veered off the road and into the water is unknown, yet by referring to the driver as an "old guy", a medical emergency shouldn't be out of the question.
Everything looked alright up until the truck started its right turn. Before that, the driver had the presence of mind to slow down, put his blinker on and initiate the turn. Whatever happened, it either occurred right at that moment, or perhaps sometime before, yet the elderly driver was able to remain in control for a brief period of time.
This type of crash could easily have ended much worse, especially if there were people on the sidewalk, directly in the truck's path.
Note: Mind the slightly colorful language from the dashcam car driver