What to Know A strange letter referring to a "steel furnace" event in Philadelphia has taken the Internet by storm and sparked countless memes.

Copies of the letter have been spotted in Philadelphia's Brewerytown and Fairmount neighborhoods.

The letter invites readers to attend a steel furnace event at a vacant lot on 27th and Girard Ave. on April 27.

ABBA, the 70's pop group? What do they have to do with anything? Why is the meat we ate in first grade alive in our bodies? Why do we have to become a solid steel statue? What exactly is happening on April 27? What's a steel furnace?

These are just a few of the questions being asked thanks to a mysterious and downright creepy letter taking Philadelphia and the Internet by storm.

Photos of the letter were repeatedly posted by several Reddit users who claimed an unidentified person was leaving copies of it in mailboxes and passing it around to residents in the city's Fairmount and Brewerytown neighborhoods.

“This is to inform you that all the food ate since first grade is alive in your body, especially the dead animal remains or meat since it was cooked alive and is alive in your body,” the letter reads. “Anywhere it goes now, you must go with it. That’s 365 days a year from first grade to now.”

The letter features more incoherent rambling, warning the reader that the only way to “save yourself from the every which a way of being burned alive” is to “become a solid steel statue by place yourself under anesthesia.”

The letter then refers to a “steel furnace” where “metal can be melted and the bodies of people and animals mixed with the metal to become steel unable to be hurt.”

It ends by stating that a meeting on the “building of a steel furnace” will take place at noon on April 27, 2019, in a vacant lot on 27th Street and Girard Avenue.

“What we need is a bulldozer to dig some ditches and steel furnace equipment,” the letter states. “Do attend.”

The letter quickly sparked an endless supply of memes, a subreddit, a Facebook event and even its own location on Google Maps.

Yet while the letter has led to plenty of jokes, some residents have expressed their concerns.

“Um, someone needs to look into that,” one Reddit user wrote. “Because if the writer is in any way involved with kids or vulnerable adults, things could go very badly wrong. Take it to the cops? Ask them who handles this kind of thing?”

A concerned person has started a GoFundMe page to raise money for mental health in light of the flyers. In its first day, it raised just under $1,000 from a goal of $5,000 for the Philadelphia Mental Health Clinic, a GoFundMe-certified charity where the money will be sent directly.

NBC10 reached out to Philadelphia police to see if they were investigating. A spokesperson said they haven’t received any formal complaints nor a copy of the letter. They are encouraging people to call and report it however if they have any concerns.