<p><strong>A&nbsp;wounded woman is helped to safety following a strong <a href="http://environment.nationalgeographic.com/environment/natural-disasters/earthquake-profile.html">earthquake</a> in <a href="http://maps.nationalgeographic.com/maps/map-machine#s=r&amp;c=-43.52352886550121, 172.63818383216855&amp;z=7">Christchurch, New Zealand (see map)</a>, on February 22.</strong></p><p>The magnitude 6.3 earthquake struck Christchurch during the lunchtime rush, toppling buildings and killing at least 65, according to Tuesday-morning (ET) news reports. Many more are still trapped in the rubble.</p><p>The temblor is one of several aftershocks that have rattled southern <a href="http://travel.nationalgeographic.com/travel/countries/new-zealand-guide/">New Zealand</a> since a powerful magnitude 7.1 earthquake struck Christchurch this past fall. That quake caused no fatalities. (See <a href="http://news.nationalgeographic.com/news/2010/09/photogalleries/100903-new-zealand-earthquake-christchurch-pictures/'">pictures of the earlier earthquake in New Zealand</a>.)</p><p>"This is just heartbreaking," CNN reported New Zealand Prime Minister John Key as saying.</p><p>"This may be New Zealand's darkest day."</p>