1 / 8

51720817_large_watermark__b

September 11, 2001: Into the Breach (Photo: DOUG KANTER/AFP/Getty Images)

For the full photo collection, go to LIFE.com.

In praise of 9/11 first responders

On 9/11, when terrorists flew planes into the World Trade Center towers and the Pentagon, murdering thousands, an untold numbers of cops, firefighters, and other first responders did what they so often do -- they headed straight into the smoke and flames, and set about trying to help victims, find survivors, and make everything all right. Never forget.