Derek Lake's mountain bike lies by the side of the road as cops examine the accident scene at Houston St. near LaGuardia Place in Greenwich Village yesterday. An 18-wheeler, driven by Edward Howard, struck and killed the Brooklyn filmmaker.A fledgling filmmaker was struck and killed by an 18-wheeler yesterday as he was riding his bike in Greenwich Village.

Derek Lake, 23, skidded and fell off his Trek mountain bike as he turned onto Houston St. after navigating bumpy street construction and was crushed by an oncoming tractor-trailer around 9:30 a.m., police and witnesses said.

"Oh, God!" truck driver Edward Howard, 38, cried after he stopped his truck, climbed down and saw Lake smashed underneath the wheels.

Howard lifted his arms toward heaven, and then bent down and covered Lake's body with his jacket, witnesses said.

Lake, a 2005 graduate of the School of Visual Arts, died at the scene.

His younger sister, Alexis, 22, said her brother was a free spirit who followed his dream of becoming a filmmaker to New York City. "He was never afraid of what people thought. He was his own, unique person. So many people loved him," she said from the family's home in Breesport, N.Y.

Howard was issued six summonses for equipment violations, but none was related to the accident, police said.

Lake's bike started to wobble as he tried to ride around a debris-covered metal plate covering some of the construction on Houston St. near LaGuardia Place, witnesses said.

"The bike was shaking," said Camerino Ovando, 34, who was driving a delivery van and saw the grisly crash. "He lost control and he fell down into the big truck. [The truck] was going like 5 mph."

The city Department of Transportation was reviewing whether the metal plate met safety standards. The construction is part of a city sewer project, officials said.

"Cyclists always have to be aware of their environment, but it's the city's responsibility to build and maintain safe streets," said Noah Budnick of Transportation Alternatives. He said Lake was the third cyclist to be struck and killed by a truck on busy Houston St. since May 2005.

In a twist, Lake had sworn off public transportation as a way to get to work, and on June 9 posted a photo of his new bike - his "hot rod on two wheels" - on his Web site.

He boasted how he made it from his Brooklyn apartment to his startup production company on W. 35th St. in 34 minutes - faster than the train.

Lake and his buddies wrote, directed and acted in a 14-minute short in high school promoting a computer game, "Aliens vs. Predator," and won honorable mention from PC Gamer magazine.

By the time he had graduated from the School of Visual Arts with a bachelor's in film and video, he had already written, directed and produced several films.

Lake filmed "Sans Penitence" in 2004 as his senior thesis, about four American soldiers who found themselves behind enemy lines during World War II.

"He filmed World War II at our home in upstate New York," his sister said. "That was his dream, to make films."nitence, was about American soldiers during World War II.