Mexican state oil company says toll rises to 37 in disaster at headquarters

Mexico's national company says on its Twitter account that a worker injured in an apparent explosion at its headquarters has died in the hospital, raising the death toll to 37.

Petroleos Mexicanos did not immediately provide details about the woman who died Monday. Dozens of people remain hospitalized after at least two floors of an administrative building at Pemex's Mexico City headquarters collapsed into its basement Thursday afternoon. Authorities initially described the cause as an explosion but since then have provided virtually no information about the possible cause, leading to a surge of conspiracy theories and complaints about government secrecy.

Mexico's attorney-general has said only that there were no signs of any burns or fire at the scene of the disaster.