NEW YORK – Engine conditions appeared normal and no engine alarms sounded before a Staten Island ferry malfunctioned while approaching its terminal and slammed into a pier, injuring dozens of people, federal investigators said Sunday.

A National Transportation Safety Board team said it determined that the ferry’s two forward engines facing the Staten Island dock stopped upon impact but the two rear engines were still operating.

The team has interviewed the chief engineer and crew members of the Andrew J. Barberi ferry, which was carrying 252 passengers and about 18 crew members when it crashed at the St. George Ferry Terminal on Saturday. It also has met with the management of the Staten Island Ferry.

Based on an initial interview Sunday with the chief engineer, who was in the ferry’s engine control room, “there were no engine alarms prior to the accident,” NTSB member Robert Sumwalt said.

“All conditions concerning the engines were normal prior to the accident,” said Sumwalt, adding that there were also no previous problems with the propulsion system or electrical systems.

Alcohol and drug tests were conducted on the crew members, Sumwalt said at a news conference Sunday. The alcohol tests, which were conducted by the Coast Guard, came back negative for all, and the drug tests were being evaluated, he said.

City Department of Transportation Commissioner Janette Sadik-Khan has said the accident appeared to be the result of a mechanical failure.

The ferry’s throttle failed to engage as it prepared to dock, she said, meaning the crew was unable to use the engines to apply reverse thrust and slow down.

The cause of the malfunction is unknown, she said. The 3,000-ton, 310-foot-long ferry was moving at about 5 knots, or 5.8 mph, when it hit.