New York (CNN) -- At least 57 people were injured, two critically, Wednesday morning when a New York-bound ferry crashed into a dock in Lower Manhattan, authorities 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.

"There was a large jolt," said passenger Elizabeth Banta. "It felt like we were in a car crash. ... Several people were thrown into the air and onto the ground."

Witnesses said several passengers were waiting at the top of a stairwell aboard the vessel as it approached the dock and were flung off their feet.

"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 that it was sending a team to investigate the scene, where at least six emergency vehicles remained late Wednesday morning.

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.At Least 50 Injured In New York Ferry Accident