NEW YORK (AP) — President Felipe Calderon responds to attack via his Twitter account . Grenade attack reported at a casino in Monterrey , in northeastern Mexico . Up to 30 people thought trapped in the casino because of debris .
NEW : Officials say the death toll in grenade attack is up to 40 . President Felipe Calderon responds to attack via his Twitter account . Grenade attack reported at a casino in Monterrey , in northeastern Mexico . Up to 30 people thought trapped in the casino because of debris .