article_snippet.sent: Laura Brown, who is heading up the Footprint restoration project, said A mysterious benefactor had to read letter twice before A mysterious benefactor could believe letter was real, adding that A mysterious benefactor had to have a 'sit down' afterwards .
article_snippet.sent: I had to have a sit down for a while. '
highlights_snippet.sent: Laura Brown, head of restoration, had to 'sit down' after reading letter .