BOSTON (WHDH) - A Dorchester man allegedly used a “fist-sized” piece of quartz to repeatedly strike a Quincy man on a Red Line train at JFK Station on Friday night, and the victim’s girlfriend said she had to helplessly listen to the assault over the phone.

Miranda Fowler said she was talking to her boyfriend, Zach Dimona-Viveiros, as he took the T from Wollaston to meet her in Boston, when she heard the attack.

“I just heard him say ‘whoa’ and you could tell the phone got taken away or something,” Fowler said. “No one wanted to help him. Just the fact that everyone was on the train and no on wanted to help him

Officers responding to a report of an assault in progress at JFK station around 8:50 p.m. found Dimona-Viveiros bleeding profusely from his face and head while David Washington-Halfkenny, 40, stood over him and shouted, according to transit police. Witnesses said Washington-Halfkenney began aggressively pacing within the train car and suddenly, without provocation, struck the victim in his face and head five times with a “fist-sized” piece of quartz, police said.

Officers rendered first aid to the victim until EMS arrived and transported him to a local hospital. Fowler said he suffered a broken eyesocket and cheekbone, along with numerous cuts to his face.

Washington-Halfkenney was taken into custody and arraigned Monday in Quincy District Court. 7News has learned that the day before, he allegedly clubbed someone in Boston and a warrant was issued for his arrest.

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