Searching for survivors in Mexico - Feb 1st, 2013 - International

— Authorities in Mexico City are promising a thorough investigation into Thursday's explosion at the headquarters of Mexico's state-owned oil company, Pemex.

A basement blast next to the 51-story tower killed at least 25 people and injured more than 100. Officials say the tower's basement and first two floors collapsed, and rescue workers are still searching the rubble for any survivors.