(By Christopher Livesay) Genoa, May 8 - Seven people were dead and two remained missing Wednesday after a container ship slammed into a control tower at the entry to the port of Genoa overnight. Divers were still attempting to retrieve bodies trapped in the underwater rubble. Authorities said the ship was bound for the Sicilian city of Messina and should not have been in the area when it rammed into the tower, sending it crashing into port waters. Some 14 people were in the 50-meter tower at the time of the accident, including a marine officer and nine sailors, authorities said. Four people were rescued and are hospitalized, two in serious condition. Investigators said that the container ship, the 40,500-ton, 655-foot Italian Jolly Nero, and its black box have been impounded and manslaughter probes have been opened. The captain said he lost control of the ship when the engines lost power. Officials have also pointed to some sort of mechanical failure. The accident happened during a shift change, meaning that more people than usual were present on the tower. A number of the victims were retrieved around the sunken elevator to the tower. The Jolly Nero was moving in calm conditions out of Italy's busiest port with the help of tugboats, on its way to Naples before Sicily, according to reports. Police were investigating the cause of the accident. Italian Infrastructure Minister Maurizio Lupi said possible causes included problems in the ship's engines or with the tugboat cables. "Two engines seem to have failed and we lost control of the ship," Genoa's Il Secolo XIX newspaper quoted one of the Jolly Nero's pilots as saying. Luigi Merlo, the head of the Genoa Port Authority, told the daily, "it's very hard to explain how this could have happened because the ship should not have been where it was". He added that two tug boats were pulling the ship, there was a port captain on board, and sea conditions were "perfect". "We are all utterly shocked. Nothing like this has ever happened before, we are dismayed," said the ship's tearful owner, Stefano Messina. There are an average of 14 accidents a year in the port of Genoa, according to Mayor Marco Doria. Lupi told parliament that the families of the victims had asked him to pay them tribute by "guaranteeing the safety of our ports". He then read the names of the victims. Two of them, Maurizio Potenza and Michele Robazza, were pilots for the port. Four others - Giuseppe Tusa, Davide Morella, Daniele Fratantonio and Marco De Candussio - were in the coastguard. The seventh, Sergio Basso, worked for a tugboat operator. The two who remain missing are Sergeant Gianni Jacoviello and Warrant Officer Francesco Cetrola of the coastguard. It was the deadliest maritime accident in Italy since the Costa Concordia cruise liner crashed off the coast of Tuscany early last year, killing 32 people.