Aug. 21 (UPI) -- Big Ben, the iconic 315-foot London tower containing its world famous clock and bell, won't be heard again for four years.
The chimes rang for the final time Monday at noon before construction crews began renovating the landmark.
The signaling of the hour -- 12 rings of the 13.7-ton Great Bell -- was the last time Ben will be heard until 2021. The tower in Britain's Houses of Parliament, built 157 years ago and an essential feature in the London skyline, is ringed with scaffolding.
The bell won't ring during the manual work to protect workers' hearing and safety.
The decision to temporarily end the chiming sparked debate in British government.
"Of course we want to ensure people's safety at work but it can't be right for Big Ben to be silent for four years," Prime Minister Theresa May said last week. The House of Commons Commission said it will review the plans and see if the work can be done quicker.
Cabinet minister David Davis said the government, which approved the renovation plans, was inadequately advised. He said had it known that one of Britain's most endearing symbols would be silenced, officials would have reconsidered the matter.
Davis said there was "hardly a health and safety argument" for quieting Big Ben during the renovation.
Britain's Trades Union Congress, which represents 5.6 million people across Britain, disagreed.
When "Big Ben bongs, you'll know it," a TUC statement said. "At nearly 120 decibels, it's like putting your ear next to a police siren."
The name Big Ben actually refers to the bell, which is over seven feet tall, but has come to signify the entire tower. The repairs will cost $37 million.
If work does take four years, many events will come and go by the time Big Ben chimes again -- including the 2018 and 2020 Olympic Games, the next James Bond film (set for 2019), Britain's exit from the European Union, and the next U.S. presidential election.