The MBTA says riders should expect severe Red Line delays in both directions due to a medical emergency at Downtown Crossing Station.

A person was trapped under an northbound train, T spokesperson Joe Pesaturo told BostInno in an email. Emergency personnel are on the scene, and the cause of the incident is under investigation, Pesaturo said.

An update on the T’s website at 2:45 p.m. states Red Line service between JFK and Kendall Stations has been suspended until further notice. Shuttle buses have been called in to replace Red Line train service. The T has asked riders to use the Orange Line and Green Line when possible.