A Philadelphia sheriff's deputy shot and killed a dog that attacked him Monday morning when he tried to break up a fight between two men outside the city's One Parkway office building at 16th and Arch Streets, officials said.

The dog belonged to one of the men involved in the fight, a Sheriff's Office spokeswoman said.

She said the men got into the fight about 8 a.m. and the deputy tried to break it up. The dog then attacked the deputy, the spokeswoman said. Police said the deputy fired twice, killing the dog.

The Sheriff's Office is investigating the shooting.