Jul 6, 2016 1 min read

PITTSBURGH (AP) – Norfolk Southern has blasted loose rock from a Pittsburgh hillside that was threatening to tumble onto its railroad tracks and a busy city road below.

The blast went off a few minutes before its scheduled 6:15 a.m. start time Wednesday.

The rock has been a problem since a boulder tumbled down onto West Carson Street and was struck by a car last week.

Railroad spokesman Rudy Husband says that incident made it clear that other rock slides were threatening its freight tracks at the foot of Mount Washington. He praised PennDOT and the state Department of Environmental Protection for helping the railroad get the necessary permits over the holiday weekend to blast away the loose rocks.

The tracks carry about 50 to 60 trains daily and are a key link between New York and Chicago.