A frightened Houston-area elderly woman accidentally killed her young firefighter neighbor earlier this week after mistaking him for an intruder, according to a report by KHOU, the CBS affiliate in Houston.

Sam Keen, 27, a Houston Fire Department fireman, had been out celebrating St. Patrick's Day with colleagues on Monday night.

After a night of drinking, Keen took a cab home but instead was unwittingly dropped off in front of his neighbor's house.

"No one did anything wrong. It was just a confluence of events that provoked a tragedy," said Mayor Parker, according to the report. "My understanding is that the firefighter, off-duty, had been out. He did what he was supposed to do: he took a cab ride home, got dropped off in the wrong place and wasn't aware of it. Tried to get into what he thought was his house and was tragically shot."

Keen's 64-year-old neighbor, who police have yet to identify, heard noises coming from her front porch. Thinking an attempted break-in was afoot, she warned the perceived burglar that she had a gun.

She told authorities, that the man nonetheless continued his attempt to enter the home. She fired two rounds through her door before calling 911.

Keen, a newlywed who had also served in the Marines, was pronounced dead at a Houston hospital. He is survived by his wife.