GRAND PRAIRIE, Texas – The owner of a Texas skating rink said Sunday that he pushed children out of harm’s way when a parent suddenly opened fire on his estranged wife and her relatives at their son’s birthday party.

The Saturday night shootings that left six dead, including the gunman, lasted just moments, said Forum Roller World owner Walt Hedrick.

“Kids were having fun and all of a sudden: ‘Bang! Bang! Bang!’ ” Hedrick said. “It was out of the clear blue. … I didn’t know what was going on.”

The gunman, whose son was celebrating his 11th birthday, ordered the children to leave the snack area before he began shooting, said Grand Prairie detective John Brimmer. No children were killed, but four people were wounded in addition to the adults who died, he said.

Police said Tan Do, 35, of Grand Prairie and his wife were having ongoing marriage problems that investigators believe led to the shootings about 7 p.m. Some people at nearby businesses said they watched as some adults and children spilled from the rink in horror, some wearing roller skates.

“They just looked terrified,” Cody Poston, a witness, told WFAA-TV, outside the rink that was festooned with birthday decorations inside. “There’s several people crying. The kids were just kind of oblivious.”

Do’s son and his other child are safe and with other relatives, Brimmer said.