Why is mr. mallards return an example of situational irony? Would the story still be ironic if he had actually been dead?

Situational irony is when an event doesn't turn out as expected. Throughout the story, the reader expects Mr. Mallard to be dead so when he opens the door at the end it is situational irony. The story could still be ironic if he had actually been dead if Mrs. Mallard died at the end. Just when she gets her freedom to live for herself, she dies of a heart attack is situational irony because her death is unexpected in the plot line.