Millennium Crash (Watchbearers Book 1) by James Litherland

Everything goes wrong when the first research expedition from the future lands in the summer of 2000 in New York City. The master time-travel device is destroyed, the professor in charge is killed, and the rest of the travelers are scattered across that ancient metropolis. They’re stranded in the past, their project in shambles from the start, and their troubles are only beginning…