System-wide signal problems and smoke conditions near one station caused extensive subway delays through Wednesday's morning rush, affecting nearly a dozen lines.
Service on the N and Q lines was suspended for a time between Queensboro Plaza and 57th Street-Seventh Avenue because of smoky conditions at the Lexington Avenue station, but it resumed by 11 a.m. It wasn't clear what caused the smoke condition, but it hampered travel all along the line.
Instagram and Twitter uses posted photos of crowded platforms from Brooklyn to Manhattan to Queens.
Meanwhile, signal problems caused significant disruptions on nearly a dozen other subway lines, including the 1, 2, 3, 4, 5, 6, 7, F and D lines and the Times Square-Grand Central Terminal Shuttle.
The MTA says those trains resumed running with residual delays at about 10:30 a.m.
