Why London bridge is stable structure?

The original London Bridge did not have a stable structure. In fact, it collapsed several times throughout history. The first London Bridge was built by the Romans in the 1st century AD. It was made of wood and was destroyed by fire in 1212. The second London Bridge was built in stone and was completed in 1228. It lasted for about 600 years, but it also eventually collapsed due to structural problems. The current London Bridge was built in the 19th century and is made of granite and concrete. It is much more stable than the previous bridges and has not collapsed since it was built.