An Iowa man who suffered a heart attack after rescuing his 5-year-old daughter from a dog attack has died, according to police.Police from the Fort Madison Police Department were called to the scene of the attack on Friday morning, as the large dog was attacking a second man, who was lying on his back, in the front yard.As the officers administered aid to that man, who they have not identified by name, they spotted 33-year-old Robert Joseph Quick and his 5-year-old daughter, who had been bitten in the face."The dog was very aggressive and would not release the man," prompting one officer to fire a gun to stop the attack, according to a statement from police."Quick had defended his daughter and undoubtedly saved her life by his actions," according to the statement.Quick later died at a local hospital, despite "tremendous efforts" by doctors and medics on the scene, police said. His exact cause of death is under investigation, but a GoFundMe campaign raising money for his funeral expenses says that he suffered a heart attack at the scene.The dog did not belong to any of the victims but was being kept at the house for a family member, according to police. It is unclear if the dog had been euthanzied.