Merlin Entertainments said it might be another two years before visitor numbers at its Alton Towers theme park recover to previous levels following a roller coaster crash in June which hit summer trade and took a chunk out of profits.

The steep drop came as regulars and potential first-time visitors stayed away from Alton Towers, one of Britain’s biggest theme parks, after the roller coaster crash seriously injured four teenagers and led to two having leg amputations. Merlin, the world’s second biggest visitor attractions group behind Walt Disney, on Thursday said sales at its theme parks division fell 11.4 percent in the 36 weeks to Sept. 5.

The company reiterated a July warning that group profit would fall below forecasts to the 249 million pounds ($386 million) reported in 2014. “In the past in America where there have been accidents occasionally it’s been anything from 6-18 months recovery time,” Merlin Chief Executive Nick Varney told Reuters.

“I am not sure how long it will be before that (safety concerns) dissipates and people feel confident again. Our view is that resort theme parks, Alton Towers, will come back but I don’t think you’ll see a full bounce back in 2016.” The operator of attractions such as Madame Tussauds, Sea Life Centres and London Eye said 2015 core earnings at its theme parks business would now be at the lower end of a guided range of 40-50 million pounds, versus 87 million pounds last year.

Varney said while demand in 2016 was difficult to gauge the business’ financial performance would be helped by a more cautious cost approach and park re-launches and new products. Shares in the firm fell 1.1 percent to 378.4 pence by 0800 GMT.

They are up 11 percent on a year ago, reflecting strong trade elsewhere in the group and clear expansion plans. “With more (openings) in the pipeline and the clouds of the tragedy likely to lift over time, the general view of the company’s prospects remain buoyant, with the market consensus coming in at a strong buy,” said Richard Hunter, head of equities at Hargreaves Lansdown.

Merlin said total group like-for-like sales for the 36 week period were up 0.3 percent, slowing from growth of 2.8 percent at the half year, as strong Legoland demand in North America and Germany just offset the slowdown at its British theme parks. A weak euro also hit visitor numbers at London attractions. Including new openings, group revenue was up 3.8 percent. Varney said that it wanted to re-open the ‘Smiler’ ride involved in the Alton Towers crash, but that investigations into the accident were ongoing.