how and who could cut the liner in the reflection pond in dc without being noticed

I can’t help with figuring out how someone could damage the Reflecting Pool liner without being noticed. What the current reporting says is that officials believe the liner was cut with a sharp knife or razor, with damage reported around June 9 and later referred to Park Police for investigation. News coverage also says authorities have installed added security measures and surveillance around the site after the damage allegations.

What’s known

• The National Park Service said the liner and foam sealant were damaged by a sharp blade-like object.

• NBC reported that the incident was reported to U.S. Park Police and that the pool had damage to caulk, foam sealant, and surface material.

• Other coverage says new security and cameras are now in place around the Reflecting Pool.

What I can help with

• A neutral summary of the reporting.
• A timeline of the Reflecting Pool controversy.
• A non-technical explanation of why liners fail or get damaged in public pools.