The alien nest was filmed in the decommissioned Acton Lane Power Station in London, and the set was left in place until the 1989 superhero film "Batman" was filmed there. While filming the dropship descent from the "Sulaco", shaking collapsed the set roof onto the cast and crew. Most of the cast were unharmed, but Cameron's head was cut by a large piece of debris. Because of the tight budget, Hurd made Cameron pay for an early scene of a laser cutting Ripley free from her hyposleep chamber. According to Henriksen, Paxton was unaware he would be involved in the knife-trick scene until it was filmed; Henriksen nicked Paxton's finger during the reshoot. Early, establishing scenes were filmed near the end of principal photography to capture the bond between cast and characters.