After being treated for cancer in Cuba last month, President Hugo Chavez failed to make any public appearances. It is unknown for how long he has been dead.
The Vice President of Venezuela, Nicolas Maduro, announced Chavez’s death today (3/5/13). He cited a severe respiratory infection as the final nail in Hugo’s coffin.
People being treated for cancer are naturally in an immuno-compromised state, so such an infection would not be uncommon.
Maduro called this, "[Chavez’s] most difficult hours".