The worst of Hurricane Sandy may be over, but the storm will have big effects on the nation for weeks to come. With many of the companies whose shares are included within the Dow Jones Industrials (^DJI 0.06%), the storm hit particularly close to home.

Johnson & Johnson (JNJ 0.67%) has its corporate headquarters in New Brunswick, N.J., as well as several subsidiaries in Pennsylvania that bracketed the storm's path. Because of Sandy, J&J not only closed its headquarters but also decided to postpone its investment analyst day on Thursday. Many had expected the presentations to focus on the company's nearly $20 billion acquisition of Synthes, whose U.S. headquarters is on the outskirts of Philadelphia. The company said the meeting will probably be rescheduled for a date next year.

Merck (MRK -0.11%), which is headquartered in Whitehouse Station, N.J., urged employees to stay out of the office because of the storm. A spokesman for the company said Merck encouraged work-from-home arrangements. Interestingly, Merck decided earlier this month to move its headquarters to nearby Summit, which is substantially closer to downtown New York City.

In Fairfield, Conn., where General Electric (GE -1.75%) is headquartered, Sandy knocked out power for 97% of the town's customers. The state's governor warned of "Katrina-like" flooding potential for the area, which lies along Long Island Sound and was thus particularly susceptible to Sandy's storm surge. Even today, the town remained in a state of emergency.

Even well off the coast in Hartford, United Technologies (RTX -0.04%) told employees to take measures to make sure their families remained safe. With mandatory evacuations and road closures throughout much of the state, the move helped emergency vehicles get through.

And of course, many Dow stocks are headquartered in New York City. They'll feel the effects of Sandy for some time, as city officials are unsure when subway service will be fully restored.

Working hard but staying safe
Companies that are big enough to be in the Dow obviously have operations around the nation and in most cases the world, so even with their headquarters in the line of fire, business will largely continue as usual for most employees. But disruptions at the top can have an impact throughout a company, and so it's important for the health of the entire business that they get things back to normal as soon as possible.