FRENCHTOWN TOWNSHIP, Mich. – Family and friends of 22-year-old Chelsea Bruck aren't thinking the worst. Instead, they're working shifts, walking neighboring streets and knocking on doors.

"If she was able to come home, she would have by now," said Bruck's sister, Kassie Bruck.

Bruck was last seen Saturday night at a party in Frenchtown Township. Video from that night shows the massive Halloween party, hosted by the rock group Pick Axe Preacher.

The lead singer says he hired 10 security guards and two parking attendants, but never expected more than 600 people to show up.

"Everyone kind of knows everyone out here, kind of thing, and you know this is kind of heartbreaking," said Michael Williams, who hosted the party.

Bruck was dressed as the character Poison Ivy and had left her phone in a friend's car.

"She called the other friend at the party, 'Hey, come grab Chelsea's phone and give it to her.' The friend came out and got the phone. That friend never was able to find Chelsea again," said Kassie.

The Monroe County Sheriff's Office released a sketch of a man Bruck may have been seen leaving the party with. Her family messaged Williams Monday morning when they couldn't reach her.

"I've been trying to talk to the mother. She didn't really want to me. I think she's kind of upset with me in a way, which I understand," said Williams.

Police have questioned Williams and searched fields around his home.

Bruck's family isn't giving up.

"It's just hope, and it's prayer, and belief in God that she's going to come home," said Kassie.