Seven of the ladder trucks in the D.C. fire department’s fleet have failed inspection and have been taken out of service.

In a statement issued Sunday night the department said seven of 17 ladder trucks, or more than 40 per cent, were found to have rust at the base of the ladder support. The department said the seven “will not return” to service “until the issues affecting them are resolved.”

Most departments have regular inspection programs in which the possibility exists that any given piece of apparatus might be found wanting. However, the removal from service of so large a proportion of any category of equipment appeared to be unusual.

Ladder trucks are major fire department resources in combating high rise fires and making rescues from upper levels of buildings.

A major part of the image of urban firefighting involves high-rise residents being taken out of the windows of burning building and down the trucks’ ladders to safety.

It was not immediately clear last night how often the trucks are actually deployed in the District, or the total number of calls on which they are sent.

Also unclear was how frequently the trucks have been inspected, or how the corrosion occurred. Details on the age of the equipment and other aspects of their maintenance history were not immediately available.

Inspections of the trucks “are part of a preventive maintenance plan for vehicles within our fleet,” said Interim DCFEMS Chief Eugene A. Jones. “It’s important that the vehicles our employees rely on when they respond to an emergency are safe.”

The ladders on the trucks can reach from 15 feet to 135 feet.

Those trucks that remain available will be rotated to various locations to provide coverage throughout the city, the fire department said.

The department said it would increase the staff assigned to the operational trucks to bolster efficiency.

In addition, the department said it would ask for help from neighboring jurisdictions when needed. It said Prince George’s and Montgomery counties have agreed to help.

Get updates on your area delivered via email