US 9 1 1, how long has the ruins of the Twin Towers been cleaned up?

The fire in the ruins of the World Trade Center lasted for three months, and rescuers spent more time cleaning up the ruins. Some samples of the wreckage were sent to the National Institute of Standards and Technology for testing, including a steel bar that was hit by an airplane. Five months after the attack, the last survivor recovered and was discharged. Six months after the incident, 6.5438+0.5 million tons of rubble on the World Trade Center site were thoroughly cleaned up, and rescuers continued to clean up underground.