Metropolitan Line: No service between Chalfont & Latimer and Chesham while we fix a signal failure at Chesham. SEVERE DELAYS between Harrow-on-the-Hill and Aldgate / Uxbridge due to an earlier fire alert at Willesden Green and MINOR DELAYS between Moor Park and Watford. GOOD SERVICE on the rest of the line. London Buses are accepting tickets via any reasonable route.