BERELIN: Three patients were killed and many people were injured, one of them critically, in a fire that broke out overnight at a hospital in the German city of Hamburg, authorities said on Sunday.Firefighters were alerted to the blaze at the hospital, the Marienkrankenhaus, shortly after midnight. It broke out in a room in the geriatric ward, on the ground floor of the building, and spread to the facade of the floor above. Smoke spread across the building’s four floors.It wasn’t immediately clear what caused the fire.The fire department said that three adult patients were killed and more than 30 people injured, the German news agency dpa reported. Of those, one was in life-threatening condition, 18 had serious injuries and 15 were slightly hurt. Authorities initially gave a higher figure for light injuries and said two people were critically hurt.A section of the hospital had to be evacuated. Injured patients were treated mostly at the hospital itself, though two were taken to nearby clinics. The fire was extinguished within about 20 minutes.Firefighters said they found several patients at the windows calling for help. People were rescued using ladders and through the building itself.