Alarm on ISS Forces Crew to Abandon NASA Side of Station

Early Wednesday (1-14-15) an alarm aboard the International Space Station sounded, forcing the

complete crew into the Russian side of the station.  

From the C/Net article:

• Flight controllers in Mission Control at NASA's Johnson Space Center in Houston saw an increase in pressure in the station's water loop for thermal control system B then later saw a cabin pressure increase that could be indicative of an ammonia leak in the worst case scenario...

Complete C/Net ISS article HERE