CHICAGO — Moments after a woman ran up to a Northwest Side birthday party asking for help, witnesses say, someone in a passing vehicle fired shots at the group, sending four people to area hospitals and leaving one woman in critical condition.

Legacy Dance Association in Humboldt Park was hosting a birthday party Saturday night, according to co-owner Reynaldo Sanchez, who said all was quiet until a woman ran up to the party around 1 a.m. and asked for help.

“It’s just by chance that she picked this place,” Sanchez said.

Sanchez said according to people at the party, the woman told a group of people outside the studio that she was in a fight with her boyfriend, and moments later someone driving by the party fired shots at the studio.

Neighbors say they heard several gunshots. Four people were struck by bullets.

Police confirm a 19-year-old woman entering the party was shot in the neck, and is now in critical condition at Stroger Hospital. A 30-year-old woman was also hit in the arm, and is in good condition at Norwegian American Hospital. It’s unclear if either are the one witnesses say was seeking help.

Two men were also shot. A 24-year-old man shot in the lower back is in stable condition at Norwegian American Hospital. The other,  a 21-year-old shot in the hand, is in good condition, police say.

Sanchez said most of the victims were inside the party at the time, and police returned to the scene Sunday to view surveillance cameras that showed the group inside hitting the floor as shots rang out. Sanchez said two off-duty members of law enforcement were working security for the party as well.

Three massive bullet holes can still be seen in the front window of the studio, but the show went on Sunday, as one group came in to rehearse for an upcoming salsa competition.

Area North Detectives are investigating.