January 9, 2013 -- Updated 1548 GMT (2348 HKT) "Several people were thrown into the air and onto the ground," a passenger says New York (CNN) -- At least 50 people were injured Wednesday morning when a ferry crashed into a dock in Lower Manhattan, authorities said. One person is in critical condition and being treated at a nearby hospital, police said. It was not immediately clear what caused the crash, which occurred around 8:45 a.m. Emergency crews carted several passengers on stretchers toward ambulances and there was a gash on the front of the vessel. Support boats circled the area. "There was a large jolt," said passenger Elizabeth Banta. Witnesses said several passengers were waiting at the top of a staircase as the ferry approached the dock and they were flung off their feet when the crash occurred. "I saw a lot of bleeding heads with white bandages (and) a lot of people strapped to boards," said Julie Westfall, who witnessed the incident. The ferry, operated by Seastreak, provides daily service between New Jersey and Pier 11 near Wall Street and carries roughly 400 passengers at a time. The National Transportation Safety Board said Wednesday it's sending a team to investigate the incident. In 2010, a ferry boat that apparently had mechanical problems crashed into the Staten Island Ferry terminal, injuring 36 people. That ferry, the Andrew J. Barberi, was the same vessel involved in an October 2003 crash that killed 11 people and injured 42, considered one of the worst ferry accidents in the city's recent history. CNN's Alison Kosik and Susan Candiotti contributed to this report.