Brooklyn —

For decades, commuters in Brooklyn relied on the G train primarily to connect them to Manhattan-bound trains. In recent years, ridership of the G has risen with the influx of new residents into Williamsburg and Greenpoint, as well as with the extension of the line, connecting riders to booming Brooklyn neighborhoods like Carroll Gardens and Park Slope.

Statistics released earlier this year show subway ridership at levels not seen since the 1940s, with Brooklyn leading the spike. Two G train stops – Flushing Avenue and Court Square – were among the top 10 stations in logging increased MetroCard swipes.

But the G train boom has brought growing pains in the form of frequent service and maintenance issues, commuters say. For many riders, a derailment Thursday caused by a crumbling wall underscored the G train’s mounting importance – and vulnerability.