Retiring aggregates CEO looks back on rockiest year in career.

• Position: Triangle - Interview

Steve Zelnak, 65, became president of Martin Marietta Corp.'s aggregates division 27 years ago and led it through its spinoff and initial public offering as Martin Marietta Materials Inc. in 1994. The Raleigh-based company is among the nation's three largest producers of construction aggregates--including crushed stone, sand and gravel. Zelnak hands over the CEO title to Ward Nye, 47, this month but will continue as executive chairman. Next summer, he'll become nonexecutive chairman.

Can you put the past year into context?

This downturn is the most severe, in terms of percentage of volume decline, since the 1930s. When I came into the business in the early '80s, that was the most severe downturn since the 1930s, and we've gone deeper this time.

You've stayed profitable--netting $176 million last year and $57 million in the third quarter--despite declining sales. How?

We began to pull in our cost structure in late 2006, a good year before most players in our industry. We pulled in discretionary expense. We reduced hours. We cut personnel, and we've been doing that steadily ever since. In December 2005, we had 5,757 employees. In September 2009, we had 4,643. We've never had to reduce employment like this, but those are the times we're in, so we have to make the moves that keep us profitable.

Overall, your costs don't seem to have changed much.

Some are freight-related, which are not controllable in the same way. It just depends on which customers were shipping. Our mix tilted toward higher costs simply because of the freight that was embedded in it. Also, we had a big spike in energy costs.

What parts of your business suffered most?

We've taken the toughest hit in the Southeast, in the Carolinas and Georgia. With the decline in housing and industrial/commercial construction and also problems the states had with their transportation budgets, we've seen very sharp retrenchment.

Where have you been strongest?

The farm belt in the Midwest. That economy has been much steadier. We had a record...