HOUSTON, Texas (KTRK) -- A bridge on a walking trail in downtown Houston has collapsed.The Buffalo Bayou Partnership said erosion on the bank of the bayou caused the trail to buckle between the Travis and Milam bridges.The organization has not yet pinpointed the cause of the collapse, but it did acknowledge last weekend's rain in the city as well as a water main break as possible reasons.Houston Public Works shut off the water in that area.The trail is closed, and there is no timeline on repairs.