I missed a connection at Frankfurt. Lufthansa tickets and flights.
I knew exactly where we had to go and exactly how long we had to get there - 30 minutes from notional arrival to departure due to a 12-hour delay in Singapore.
I'd had the entire flight from Singapore (thanks to in-flight WiFi) to plan my run through the airport so was ready, and nearly made it.
On the flight out of Singapore was given some comfort by a regular flyer who said that this flight usually arrived 30 minutes early, but as it turned out, we arrived dead on time, so we had 30 minutes.
I left our travelling party behind and ran all the way and made it to the departing gate while crew were still there, with 10 minutes before departure, but they said they'd closed the flight - not surprised. If I hadn't had to go through a secondary bag screening because I was carrying a drone and a camera in my carry on, I might have made it before they'd closed the flight, and then might have convinced them to hold the flight open for the other three in my party who were a few minutes behind me. But I didn't.
As it turned out we landed at the furthest gate (E10, so not only had to clear passport control), but get 2.2km to the A gate where our departing flight was leaving from).
I was pretty pleased with my effort, even if I failed.
It was an impossible connection, due to a delayed departure out of SIN. I knew it was impossible 48 hours before I missed it but couldn't do anything about it; despite calling my travel agent and Lufthansa, was basically told "they'll fix it in Frankfurt if you miss it".
When I back tracked to customer service, the security guard at the customer service desk (yes, they needed one) asked what I wanted and I explained, and he said "oh, that's an impossible connection".
When I got to the counter, the CSA said "oh, that's an impossible connection" and went looking to re-book four people in J to Reykjavik. I hadn't been able to find any flights for a couple of days, but, to her credit, she found flights the next day via Geneva, including a leg on Swiss from Frankfurt to Geneva, and then Iceland Air from Geneva to Reykjavik.
Iceland Air had great in-flight service, and brilliant lost-bag tracking and delivery service, since only one of our three bags made it onto the first flight out of Frankfurt. The others took between 3 and 7 days to follow.