An enormous radio telescope in Puerto Rico that had been used by scientists to track asteroids and study planets, has collapsed.
It was featured in Hollywood films including "Contact" with Jodie Foster in 1997 and the James Bond film "Goldeneye" in 1995.
The US National Science Foundation (NSF) said the platform fell on Tuesday with all three of the 305-metre telescope's support towers breaking off.
"We are saddened by this situation but thankful that no one was hurt," said NSF Director Sethuraman Panchanathan.
"Our focus is now on assessing the damage, finding ways to restore operations at other parts of the observatory, and working to continue supporting the scientific community, and the people of Puerto Rico."
Workers who were in the control room as the event unfolded said they heard a loud bang when it began to collapse.
The telescope, which until 2016 was the largest of its kind, also played a role in countless scientific discoveries.
It was used to conduct research that led to the discovery of a new binary pulsar to help study gravitation, a triumph by two scientists who were rewarded with the 1993 Nobel Prize in Physics.
The telescope was built in 1963 with money from the US defence department.
In August, one of the telescope's cables "unexpectedly" detached, causing damage to the platform. A second cable broke on November 6, at 60% of its minimum breaking strength, meaning it was likely the remaining cables were weaker than expected, the NSF said.
The foundation had planned to close the radio telescope, which was used by around 250 scientists.
After it collapsed, many scientists posted stories about what the telescope had represented for them with the hashtag #WhatAreciboMeansToMe.
Meteorologist John Morales wrote in the Bulletin of Atomic Scientists that the collapse "marks the end of an era."
"For Puerto Ricans, it’s a blow to our pride," he added.