The Metropolitan Police Department is facing a shortage of officers.

Chief Cathy Lanier told a D.C. Council hearing the department’s hiring can’t keep up with the rate of retirements and officers quitting.

The head of the police union, who has been warning about this problem for years, said it has become a crisis.

Lanier said she’s looking to civilianize more than 100 positions currently held by sworn officers to help alleviate the problem.

She acknowledged more than 300 officers left the department last year and more than 400 are expected to leave this year. Lanier called the problem a retirement bubble, but almost half of those who left the department last year resigned before reaching retirement.