more now from gary tuckman in new york. >> reporter: life-threatening flash flooding in america's largest city creating large-scale problems. many houses and apartments inundated, particularly in the new york city burro of brooklyn. one brooklyn man said when he woke up at 8:00 a.m., the water was at his knees. >> within about ten minutes, it was waist high. >> reporter: this was the scene at one of the city's largest parks. prospect park in brooklyn. >> how am i supposed to get across there? are you serious? >> reporter: cars, trucks, buss, driving through flood waters. the huge new york city subway system impacted with raging rapids pouring downstairs. it caused signal issues delay ing some of the subway lines and getting to aurpts, a challenge for many. on the grand central parkway on the way to laguardia in queens, flooded roadways. the new york city mayor warning people earlier in the day to stay in place, whether they were at home, work or in schools, which were open. >> i am issuing a state of emergency for new york city base ed on the weather conditions. i want to say to all new y