Minneapolis fire investigators believe someone may have intentionally started a fire that torched a block on West Broadway Avenue last April.

Recent tests of wood samples from the back doorway of the building where the fire started confirmed the presence of an ignitable liquid. Sgt. Sean McKenna, a fire investigator with Minneapolis police, and other officials are asking the public for clues.

"There are answers out there somewhere," McKenna said. "This is a busy street [with] passersby. I believe somebody knows what happened, and we would like the public's help."

McKenna says a caretaker of the building where the fire started passed through the back stairway 15 minutes before the fire was detected, suggesting the blaze grew abnormally fast.

Anthony Newby, executive director of Neighborhoods Organizing for Change, said he doesn't know who would have intentionally set a fire that torched a block of West Broadway Avenue in Minneapolis, at a press conference on July 28, 2015. Laura Yuen | MPR News

No one was hurt, but businesses, including Neighborhoods Organizing for Change, and about 20 residents were displaced. Some of the buildings will likely be torn down.

NOC Executive Director Anthony Newby says it's still unclear who would have started the fire and what they were targeting.

"We have no idea," Newby said. "The only information we have has come directly from the city, and we're told there are no leads today. Lots of speculation, lots of potential motives, and we just don't have anything concrete as of now."

One of the displaced residents is Terrance Cargill. He was living at 913 Broadway Avenue when the fire woke him up.

"Since then I lost everything — everything but my life," Cargill said. "I always felt something was funny about how that fire got so quickly spread."

Authorities are asking for anyone with information about the fire to call the arson hotline at 1-800-723-2020.