All morning trains on Metra’s Heritage Corridor service were canceled Monday morning following a freight train derailment in the southwest suburbs. About 3 a.m., the transit agency was informed of a freight train on the Canadian National Railway derailing and blocking both Metra tracks between Lockport and Willow Springs, according to a Metra spokesman. As a result, the three morning trains on the Heritage Corridor line, which runs from Joliet to Chicago, were canceled, Metra said. The first Heritage train had been scheduled to leave at 5:45 a.m. Passengers are advised to take the Rock Island Joliet, BNSF and Southwest Service lines as alternative transportation.