A smoking helicopter veered suddenly and plunged toward the water. An alarmed motorist on the Interstate 526 bridge over the Wando River called 911.
A life and death drama was playing out for rush-hour traffic on Wednesday.
Police patrols and three Charleston Fire Department trucks and a battalion chief raced to see what was happening, said Mark Ruppel, public information officer.
Only a Charleston police officer driving on the bridge took it calmly. The helicopter, the officer realized, was only 2 feet long.
"He spotted it and realized it was a toy," said Charles Francis, police public information officer.
The officers spoke with two people below the bridge who were playing with the remote control aircraft.