Michael Casey/Associated Press

OceanGate co-founder Stockton Rush said the carbon fiber hull used in an experimental submersible that imploded was developed with help of NASA and aerospace manufacturers, but a NASA official said Thursday that the agency had little involvement and a Boeing official said some recommendations were ignored.

An Associated Press analysis has found a growing number of hazardous dams in poor condition across the U.S. The AP tallied more than 2,200 dams in poor or unsatisfactory condition that are rated as high hazard, meaning their failure likely would kill someone. That figure is up substantially from a similar AP review three years ago. Experts say the increase is a result partly of deferred maintenance and new development downstream from old dams that weren't necessarily designed to today's standards. The federal government's National Inventory of Dams has been updated to make the conditions of many dams public, but some agencies still withhold that information.The number of high-hazard dams in deficient condition in South Carolina rose by a third from 2018 to 2021.