MANILA, Philiippines — The Department of Public Works and Highways (DPWH) is mounting a broad emergency response to infrastructure and flooding threats, citing a damaged EDSA Magallanes Flyover in Makati City and clogged waterways that triggered flooding in parts of Metro Manila.Public Works Secretary Vince Dizon said on Thursday that DPWH teams moved quickly after receiving reports of falling debris from the southbound Magallanes Flyover, promp…