In a huge advance for investigators, divers battling murky, choppy seas found one of the two flight recorders of Swissair Flight 111 on Sunday, as well as three large pieces of wreckage believed to be the plane's fuselage.

Vic Gerden, the chief crash investigator, said the flight-data recorder would be flown to a laboratory in Ottawa for examination. If in good condition, it would provide more than 100 types of technical data that could be of vital help in explaining why the MD-11 jetliner plunged into the sea Wednesday, killing all 229 people on board.The so-called black box and the wreckage were found five miles offshore at a depth of 190 feet by divers working with hand-held sonar devices. Gerden said the divers were able to work at that depth for only about seven minutes at a time, with their visibility limited to about 10 feet.

The discoveries were a major breakthrough for investigators, who previously had gathered little concrete evidence to assist their probe into why the plane's cockpit filled with smoke and why the cockpit crew's emergency conversation with traffic controllers was cut off six minutes before the crash.

Divers will continue searching for the second black box - the cockpit voice recorder that would reveal other noises in the cockpit in addition to the already available conversation with controllers.

Help for the searchers was on its way. The USS Grapple, a U.S. Navy rescue and salvage ship that assisted in the deep-sea investigation of the TWA Flight 800 crash in 1996, embarked Sunday from Philadelphia, bound for the search area.

The ship, expected to arrive Wednesday, carries equipment capable of lifting 300 tons, plus more than 30 divers able to reach depths of up to 190 feet.

On land, victims' families and residents were still trying to come to grips with the tragedy. More than 300 family members have flown to Halifax from New York, the plane's starting point, and Geneva, its intended destination.

"This has been a horrible week," said the Rev. Richard Walsh, pausing to choke back tears in his sermon at St. Peter's Anglican Church in a coastal town near the search site.

"I'm sorry, I'll be OK," he told his congregation after a pause.

The Swissair plane crashed 16 minutes after the pilots reported smoke in the cockpit and decided to attempt an emergency landing. The plane started toward the Halifax airport but made two sharp turns as it tried to descend and dump fuel.

In Zurich, Switzerland, Swissair officials said they had reconstructed the final phase of the flight, based on information from Canadian investigators. They said the plane couldn't have made a direct approach to Halifax from where it made the first distress call because it was flying too high and was too heavy.

The call was made 70 miles out of Halifax, but the pilots would have needed 130 miles to make a direct landing, Swissair's chief pilot, Rainer Hiltebrand, said. However, he said attempting to land in Halifax was still better than trying for Boston, which thepilots initially suggested to controllers.

Swissair said memorial services for victims would be held Friday in New York, Geneva and Zurich. A series of memorial services was planned over the next several days in Halifax and surrounding towns.

Walsh, at one of the services, said residents of the region would remember these tragic days for the rest of their lives.

At a military air base outside Halifax, pathologists continued the grim and technically difficult task of trying to identify the badly fragmented human remains that have been retrieved from the crash site thus far.