INDIANAPOLIS -- A woman was killed when she tried to break up a swordfight between her brother-in-law and a grandson in her home on Indianapolis' far-northwest side early Thursday morning.

Franziska Stegbauer, 77, died as a result of stab wounds, Indianapolis police Sgt. Matt Mount said.

Chris Rondeau, 39 and Adolf Stegbauer, 69, got into an argument at a home in the 5200 block of Raceway Road at about 1 a.m. that escalated when one of the men grabbed a sword, prompting the other man to also brandish a sword.

Police were initially unsure if Franziska Stegbauer's death resulted from stab wounds or from a medical condition brought on by the fight.

Investigators are trying to determine which man stabbed the woman, but Rondeau was already being held on an attempted murder charge because of wounds that Adolf Stegbauer suffered.

Adolf Stegbauer was listed in critical condition at Wishard Memorial Hospital Thursday afternoon after undergoing surgery.

"We're unsure yet who started this fight, how the swordplay got involved," said Indianapolis police Sgt. Matt Mount. "We're not sure who it was who stabbed the woman. We'll have to do some testing on the swords and figure out who had which sword, whose blood is on which sword."

Rondeau, who was also hospitalized with stab wounds, was held Thursday afternoon at the hospital's detention unit