Officials say at least two people were killed and at least 22 injured after a pair of New York buildings collapsed.<br/> <br />The two five-story buildings, with a total of 15 apartments on a residential block in Upper Manhattan, were brought down by an explosion.<br/> <br />It's believed to be caused by a gas leak around 9:30am.<br/> <br />New York Mayor Mayor Bill de Blasio:<br/> <br />(SOUNDBITE) (English) BILL DE BLASIO, NEW YORK CITY MAYOR, SAYING:<br/> <br />"The impact affected buildings around the two that were destroyed, very heavy impact on the surrounding buildings. A heavy fire has ensued as well."<br/> <br />Officials say there was no advance warning of a gas leak.<br/> <br />…Except for a call made to Con Edison, complaining of a gas leak, about 15 minutes before the explosion.<br/> <br />(SOUNDBITE) (English) BILL DE BLASIO, NEW YORK CITY MAYOR, SAYING:<br/> <br />"This is a tragedy of the worse kind, because there was no indication in time to save people. We know we've lost two people already."<br/> <br />Officials won