This broken rail, which officials say would not have caused a derailment happens just days after a broken rail is believed to have caused an accident on Friday.
Tuesday's incident was unveiled at 3am when a special car found the cracked rail, and officials had the crack fixed by 7 a.m.
Express trains were briefly moved to the local track.
"I've experienced a lot of delays on my way to work in the morning," said one traveler.
The crack was found during normal track inspections.