This is why we can't have nice chemistry classes (or the Internet): Some teenagers are using their knowledge about the chemical reaction between Drano and aluminum foil for evil. Residents near P.S. 178 in Washington Heights say "Drano bombs" have been exploding in and around the school all weekend, with the first blast reported around 11 p.m. on Friday. "It sounded like fireworks," local resident Valerie Castillo tells the Daily News. "I thought it was little kids playing because I heard kids running." Apparently, the junior Weathermen came back for more on Saturday.

A custodian at the school heard one of the bombs burst against a school door around 11 a.m., saw a white substance, and called 911. The FDNY and police bomb experts reported to the scene and found 20 exploded bottles in the area. Four of the makeshift bombs were found under two cars parked near the school, the Post reports. "Usually around the Fourth of July we deal with that," a local mom tells the News. "Now when we find out it's something haz-mat has to come and dispose of, that's a little scary." In other Washington Heights news, some bonehead threw an M80 near a baby stroller Saturday, setting it briefly on fire. The baby was physically unharmed.