Amtrak has halted all train service between Baltimore and Washington, including MARC Penn Line trains, due to a major water main break in Maryland.

Baltimore Public Works spokesman Kurt Kocher says a 36-inch water main broke on Washington Boulevard in the Halethorpe area, north of the Baltimore Washington International Thurgood Marshall Airport station.

Tracks in the area are covered with mud, trees and other debris. Amtrak crews are clearing the site, but service likely won't be restored until at least noon. Amtrak said riders between Washington and Philadelphia will likely experience problems all day Wednesday.

The Maryland Transit Administration is running shuttle buses for MARC riders between Penn Station in Baltimore and Odenton.

Six schools in the area closed because of the water main break.