The tunnel connecting passengers with the plane collapsed just before 8pm local time (1am GMT).
Flights were grounded and multiple emergency medical services were called on the scene.
The area has been sealed off.
The six victims have reportedly been rushed to hospital.
However, it appears their injuries are non-life-threatening.
The airport wrote on Twitter: “Partial equipment failure involving jet bridge at BWI Gate E-10.
“BWI Fire & Rescue Dept responded, along with mutual aid.
“Preliminary info indicates 6 individuals transported to local hospitals with non-life-threatening injuries.”
Baltimore Washington International airport is located only nine miles south of Balitmore and 32 miles northeast of Washington.
The airport’s site claims it is the “busiest airport in the region” and it is named after Thurgood Marshall, a US Supreme Court justice and civil rights advocate.
More to follow…