Complex sentence: Rama I's grandson, King Rama III (1787--1851), decided to build a chedi of huge dimensions inside Wat Saket, but the chedi collapsed during construction because the soft soil of Bangkok could not support the weight.
Split into simpler sentences: Rama I's grandson, King Rama III (1787--1851), decided to build a chedi of huge dimensions inside Wat Saket. Unfortunately, the chedi collapsed during construction because the soft soil of Bangkok could not support the weight.