City officials are trying to find out why a 10-inch terra cotta pipe broke and spilled 2,400 gallons of untreated sewage in Manoa.

The break near 2112 Metcalf St. was reported to the city’s Department of Environmental Services at 5:40 p.m. yesterday. The sewage overflowed a manhole into the street and into a storm drain that flows into the Ala Wai Canal. Another 100 gallons dissipated into the ground. City crews secured the site at 7 p.m.

The Department of Health was to begin water sampling the area this morning.