Hollow is not automatically dangerous, and this is where homeowners get oversold more than anywhere else on this list. A tree is a tube, and a tube carries bending load in its outer wall — a hollow stem with a thick continuous shell can be as strong as a solid one. What actually matters is the thickness of remaining sound wall relative to trunk radius, and whether the cavity is closed or has an open slot in the side. An open slot is worse than a sealed hollow of the same size because the tube can no longer resist flattening inward. Neither of those is visible by looking at the hole. In Cumberland — Old Town Cumberland / Cumberland Historic District, Cumberland Heights and Glen Oaks Village included, that's normally a hazardous tree removal job at $800–$5,000. Within weeks.
Why this comes up in Cumberland
Cumberland was platted on the National Road in 1831 and did not incorporate until 1951, so Old Town along US 40 is genuine 19th- and early-20th-century stock — Folk Victorian, Craftsman bungalow and American Foursquare, with 1800s outbuildings still standing near Washington Street. Nearly all growth since has been east into Hancock County; the town's own profile puts the 2023 estimate at 6,419 with a median home value of $204,600.
Cumberland's canopy
The biggest and oldest trees stand in Old Town along US 40, over houses on a corridor continuously settled since 1831 — that is where a crew will meet 100-plus-year specimens with structures under them on both sides. Buck Creek carries the bottomland canopy, the east-side Hancock County subdivisions date from the 1970s through the 2000s and their canopy is mid-life, and ash has been removed across central Indiana by emerald ash borer; no published street-tree inventory exists for the town.
Marion County (town limits extend east and north into Hancock County) County rules
The Town of Cumberland code has no tree chapter and no permit for removing a tree on private property. What it does regulate: no trees or shrubs planted in any drainage easement without Stormwater Board approval; a required plat covenant keeping clear sight triangles at corners, with no trees permitted to remain in the triangle unless the foliage line is high enough not to block sight lines; and a ban on attaching signs to any tree in a public way. The critical wrinkle is jurisdictional: Cumberland only issues permits and enforces code in its Hancock County portion. Marion County properties go to Indianapolis instead, whose code requires approval from the Division of Construction and Business Services of DBNS plus the Board of Parks and Recreation before an abutting owner uses the curb-to-sidewalk plot for a tree row (the exact section number is UNVERIFIED — sources give both 645-514 and 645-561).
The tree lawn in Cumberland
It depends which side of the county line the address falls on. On the Marion County side, the plot between curb and sidewalk is city right-of-way and the abutting owner may use it for grass or a tree row only with Indianapolis DBNS and Board of Parks and Recreation approval. On the Hancock County side, Cumberland's own permit office has jurisdiction, and the town's code contains no street-tree program at all. Same street, different answer.