One of the three high-speed elevators on N. Moore Street — which are less than a year old — broke down about 8:15 a.m., according to scanner traffic.
A commuter who was rushing to work after being freed from the elevator said the group remained calm as they waited for help.
The entrapment was caused by a power surge that is under investigation, WMATA spokeswoman Caroline Laurin said.
The elevators went out of service in December 2013 because of an electricity-related glitch.
All three of the elevators on N. Moore Street were taken out of service after the incident and had resumed operation by 11:15 a.m., the WMATA representative said.
DES spokesman Eric Balliet said authority over the Rosslyn station elevators was transferred from the county to WMATA about a month ago.