(CNN) -- Five people suffered minor injuries Friday when a duck boat crashed into several other vehicles in downtown Boston, Massachusetts.
The chain-reaction crash happened shortly after noon on a ramp from Embankment Road West to Charles Street Circle, Massachusetts State Police Trooper Thomas Murphy said. At least seven vehicles were involved.
No one was seriously hurt.
Cindy Brown, general manager of Boston Duck Tours, said a piece of fallen equipment caused the crash.
"A computer box fell off and become lodged under the brake" pedal, Brown said.
Once the driver dislodged the box, Brown said, the duck boat was able to brake normally.
Brown estimated that the duck boat was traveling between 15 and 20 mph when it crashed.
"We're re-inspecting the vehicles that are of the same configuration," Brown said.
Duck boats are amphibious vehicles often used for tours on land or water.
Two people were killed this month when a barge hit a duck boat on the Delaware River in Philadelphia, Pennsylvania.
CNN's Bradley Gallo contributed to this report.