Forty-three cars towed and impounded by the city for illegal parking were vandalized and stripped of parts Sunday, causing an estimated $1,800 in damages, authorities said yesterday.

Vandals removed tires and parts, broke into trunks and ransacked the inside of the vehicles in the I-395 impoundment lot, located in a tunnel near Massachusetts Avenue and 3rd Street N.W.

It was the third such incident within two months at the city lot.

"The government is in fact responsible for this," said John Brophy, head of the bureau of parking in the city's transportation department. He said owners of the cars will be directed to file claims with the office of the D.C. Corporation Counsel.

Brophy blamed the damage on a lack of adequate security.

He said officials decided late yesterday to double the number of officers patrolling the city lot from one to two.

According to Major Archield Twyman Jr., head of the special guard unit responsible for security at the lot, the vandalism was discovered at 4:45 p.m. Sunday by an officer on routine patrol of the lot.

He said the officer saw three men flee through a previously-locked side door of the impoundment lot.

"They were definitely professionals," said Tywman as he surveyed the damage to the vehicles.

Tires had been stripped from a brown 1972 Cadillac and a silver-colored Ford van. They sat on their rims. A tan Volkswagen van nearby had been broken open and the contents inside strewn about. The front wind-shield of a gray Vega was broken and the glove compartment ransacked. The hub caps on a brown and gold Caprice lay on the ground, where the vandals apparently started to take off the tires, but never did.

"You would think that your car would be well-protected in here," said Douglas Dann of Greenbelt.

The vandals broke a side window in Dann's 1976 Datsun and ransacked the glove compartment.

"it's disheatening," said Lloyd Sydnor, acting chief of the enforcement division in the city's department of transportation. "They (vandals) went through here like Grant went throught Richmond," he said.

The other incidents of vandalism occurred at the lot on March 31, when 15 cars were vandalized, and May 5, when seven cars were involved, officials said.

No incidents of vandalism have been reported in the city lot at 34th and K Sts., N.W., in Georgetown.