Thursday marks 20 years since Australia experienced its worst massacre. The Port Arthur rampage prompted a severe crackdown on firearms that saw more than 640,000 weapons turned in to authorities. In July 2015, NBC News took a look at the mass shooting and the landmark laws it sparked.
The question is often asked in the somber aftermath of a shooting massacre: how many deaths will it take before America changes its gun laws?
And while a political solution remains elusive, mass killings such as those in Charleston, Chattanooga and Lafayette continue with alarming frequency across the U.S. — a recent study found one occurs in America every two weeks.
But for Australia, a single massacre changed everything.
