The director of Hawaii’s airports through most of the Lingle administration abruptly resigned this month, but his departure should not abort investigations of the state Transportation Department’s airports division. Taxpayers deserve to know whether the irregularities preceding Brian H. Sekiguchi’s departure took the form of sloppy administration, lack of oversight, criminal wrongdoing or all of the above.

Sekiguchi was named head of the airports division nearly seven years ago following 22 years of military and engineering supervisory jobs in the Navy, Air Force and other periods in the private sector. He has come under fire by state Sen. Donna Mercado Kim, chairwoman of the Ways and Means Committee, in the past year for what she regarded as improper administration.

Sekiguchi gave five days notice in resigning his position Aug. 6 in the wake of stormy hearings before Kim’s committee. Most perplexing is the state’s expenditure of $876,000 a year to sublease space in a building owned by the state near Honolulu Airport.

The way that appears to have happened is that a warehouse company leased the building from the state, which then subleased it back to go forward with a plan to sub-sublease it to car rental companies, which then backed out. A state contractor for airport modernization now is allowed to use the building free of charge.

The state Procurement Office found last month that the Transportation Department had violated the law by hiring two airport security consultants last year through a contractor. The procurement administrator found that the transportation personnel lacked proper training.

Kim also has criticized the airport for awarding a $1.5 million contract for a system to monitor taxi traffic at Honolulu Airport in 2000. The system has not been completed, even though the state has spent $1.3 million for the project. And she has chastised the department for paying double for half the land it had planned to buy next to Lihue Airport.

Kim also grilled Sekiguchi about whether an airport vendor paid for his ticket to the Masters golf tournament in Augusta, Ga., in April. Sekiguchi maintained that he bought his own ticket, but Kim remained doubtful, saying, "There seems to be some improprieties going on regarding your position and regarding vendors that you have control over."

Sekiguchi’s resignation should not be taken as an admission of malfeasance or even ineptness. Further hearings, though, would be helpful in understanding what went awry during his tenure so it won’t happen again.