SANTIAGO, Chile — A fire set off during a riot in a severely overcrowded prison killed at least 83 inmates today and seriously injured at least 14 others, firefighters said.

“The conditions that existed inside this prison are absolutely inhumane,” said Chilean President Sebastian Pinera, who visited an emergency center where inmates were being treated for severe burns and smoke inhalation.

National prison police director Luis Masferrer said the blaze broke out at about 5:30 a.m. at the San Miguel prison south of the capital, and it was brought under control three hours later.

Chile’s health minister, Jaime Manalich, called it an “enormous calamity,” “probably the worst in the history of our penitentiary system.”