5 Flying boats sank in a gale. 

The incident:
Thursday, January 15, 1942, an SA strong wind hit the South West part of Iceland.  The RAF and USN had their main flying boat (harbour) station at Fossvogur, close to the Reykjavík Airfield.  At the US Weather Station at Reykjavík Airfield, the average wind speed measured
89 mph (77,3 knots) (39,8 m/s) and gusting to 133 mph (115,5 knots) (59,5 m/s). 
At about 10 o´clock the wind caused damage to electrical lines and antenna cables at the Airfield.  Roof panels started to blow off some of the Nissan huts and a supply hut and the mess hut disappeared in the high wind. 
At the Airfield several aircraft, 6 Armstrong Whitworth Whitley, 1 Lockheed Hudson, 1 Vickers Wellington and 1 Catalina were secured by cables to blocks of concrete, the concrete blocks did not hold and ground crews started the engines and held the aircraft into the wind, this worked and the aircraft were saved.
3 Catalina’s and 2 Martin Mariners were at moorings out on the Fossvogur flying boat harbour.
At 3 o´clock all 5 aircraft on the flying boat (harbour) were sunk. 
Several military personnel had minor injuries but no lives were lost in the storm. 
Crew:
No flight crew involved as aircraft were parked at moorings. 
The Aircraft:
The USN VP73 Patrol Bomber Squadron lost three Catalina PBY-5 aircraft in the storm: 
s/n 2326, s/n 2331 and s/n 2337
The Squadron had a fleet of 6 aircraft in Iceland from 9 August 1941 to 3 May 1943.
The USN VP74 Patrol Bomber Squadron lost two Martin Mariner PBM aircraft in the storm: s/n 1255 and s/n 1236
The Squadron had a fleet of 5 aircraft in Iceland from 9 August 1941 to 19 January 1942.
Source: 
USN Patrol Bomber Squadrons VP73 and VP74 history
Greinagerð VÍ 03026, ágúst 2003

USAAF 33rd Fighter Squadron, Iceland Base Command group, operated P-40 aircraft in Iceland from August 6, 1941, to June 9, 1945.

During the year 1941 the squadron experienced 13 P-40 aircraft incidents, lost 2 P-40 aircraft and one pilot was killed in a crash.


Reykjavík

Aug. 6.41. s/n 41-3424,  Meeks, George E.   Landing incident, minor damage.

Aug. 19.41.  s/n 41-13422, Meeks, George E. (P-40C Nauthólsvík)

Aug. 30.41.  s/n 41-13428,  Noel, Dana E.   Landing incident, aircraft destroyed.

Sep. 10.41.  s/n 41-13345, Stuke, Carl W.   Forced landing engine fire, minor damage.

Sep. 18.41.  s/n 41-13429, Tuman, Howard A.   Forced landing near Borgarnes, out of gas.

Oct. 01.41.  s/n 41-13444 Stuke, Carl W.   Landing incident, minor damage.

Oct. 01.41.  s/n 41-13445, Zabriskie, Lawrence C.  Landing incident, minor damage.

Oct. 08.41.  s/n 41-13464, Gingras, George D.   Ground looped at landing, minor damage.

Oct. 09. 41.  s/n 41-13462, Farley, Orville B.  Landing incident, minor damage.

Nov. 15.41.  s/n 41-13439, Bradbury, Lloyd V.   Landing incident, minor damage.

Nov. 17. 41.  s/n 41-13452, Leefburrow, Philip C.  Ground looped at landing, minor damage.

Nov. 24. 41.  s/n 41-13437, Patterson, John G. Eng. fire forced landing, minor damage.

Dec. 12. 41.  s/n 41-13463, Van Ansdell. Robert L.  Ground looped at landing, minor damage.