(J. Scott Applewhite/Associated Press)

It is the second time this week alone that Metro’s rail has experienced a problem. On Monday, there was a cracked rail at the Rosslyn station, which caused some single tracking.

At Stadium-Armory, the exact cause of the chipped rail was unknown, according to Metro chief spokesman Dan Stessel. Trains were single-tracked between Eastern Market and Cheverly from 8 p.m. until close as crews worked to fix it overnight, Stessel said.

Last week, Metro’s Red Line experienced a cracked rail between the Friendship Heights and Tenleytown stations that caused delays.

Stessel said Metro experienced six cracked rail situations last January compared to six this January, including the Rosslyn incident, that caused delays during operating hours.

“We are a system that is in need of investment and maintenance,” he said. “That’s why you see track work happening all over the system at every off-peak hour.”

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