Gaithersburg collision leaves teenager seriously injured

      A cracked helmet on the ground marks the spot where 15-year-old Nicole Polen landed just before 7 Thursday morning, around twenty feet from the walkway she was trying to cross.

      Police say Polen, a star swimmer at Gaithersburg high school, and a friend were riding their bicycles when they tried to cross Woodfield Road, right at this busy intersection with eight lanes of traffic.

      But the two teens didn't wait to cross, according to police

      Police say the girls were a little more than halfway across when a silver Nissan driving southbound struck Polen. These skid marks indicate the driver tried to slow down significantly before impact.

      The driver isn't facing charges.

      Jacob Wayerskis says this area can be dangerous for bicyclists because of the heavy traffic, especially during rush hours.

      Mother Eileen Heffernan knows how much her kids enjoy riding their bikes in the summer. And she says the accident serves as an important reminder

      "It's just scary," she says. "I always talk to my kids about being safe, but you never know."