Fire crews took more than five hours to bring a blaze at Larne’s Regal cinema under control.
An incendiary device hidden in a cassette was blamed for causing the blaze at the Curran Road premises in October 1977.
The balcony and roof were extensively damaged in the arson attack which was started in balcony seating.
However, firemen wearing breathing apparatus managed to confine the flames to that area. Police believed it had been planted towards the end of a Saturday night performance “following a pattern in the rest of the province”.
A chief inspector said that one of his officers based in a security hut outside had spotted smoke coming from the cinema. However, the area was not evacuated although key holders were alerted and advised to be vigilant.
He indicated that although these devices were small, they had “devastating results”.
Meanwhile, councillors and social workers said they feared that young people would “turn to other avenues of entertainment” following the attack on the Regal which was blamed on the Provisional IRA.